/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*  Prototype JavaScript framework, version 1.5.0_rc1
 *  (c) 2005 Sam Stephenson <sam@conio.net>
 *
 *  Prototype is freely distributable under the terms of an MIT-style license.
 *  For details, see the Prototype web site: http://prototype.conio.net/
 *
/*--------------------------------------------------------------------------*/

var Prototype = {
    Version: '1.5.0_rc1',
    ScriptFragment: '(?:<script.*?>)((\n|\r|.)*?)(?:<\/script>)',

    emptyFunction: function()
    {
    },
    K: function( x )
    {
        return x
    }
}

var Class = {
    create: function()
    {
        return function()
        {
            this.initialize.apply(this, arguments);
        }
    }
}

var Abstract = new Object();

Object.extend = function( destination, source )
{
    for ( var property in source )
    {
        destination[property] = source[property];
    }
    return destination;
}

Object.extend(Object, {
    inspect: function( object )
    {
        try
        {
            if ( object == undefined ) return 'undefined';
            if ( object == null ) return 'null';
            return object.inspect ? object.inspect() : object.toString();
        }
        catch ( e )
        {
            if ( e instanceof RangeError ) return '...';
            throw e;
        }
    },

    keys: function( object )
    {
        var keys = [];
        for ( var property in object )
            keys.push(property);
        return keys;
    },

    values: function( object )
    {
        var values = [];
        for ( var property in object )
            values.push(object[property]);
        return values;
    },

    clone: function( object )
    {
        return Object.extend({}, object);
    }
});

Function.prototype.bind = function()
{
    var __method = this, args = $A(arguments), object = args.shift();
    return function()
    {
        return __method.apply(object, args.concat($A(arguments)));
    }
}

Function.prototype.bindAsEventListener = function( object )
{
    var __method = this, args = $A(arguments), object = args.shift();
    return function( event )
    {
        return __method.apply(object, [( event || window.event)].concat(args).concat($A(arguments)));
    }
}

Object.extend(Number.prototype, {
    toColorPart: function()
    {
        var digits = this.toString(16);
        if ( this < 16 ) return '0' + digits;
        return digits;
    },

    succ: function()
    {
        return this + 1;
    },

    times: function( iterator )
    {
        $R(0, this, true).each(iterator);
        return this;
    }
});

var Try = {
    these: function()
    {
        var returnValue;

        for ( var i = 0; i < arguments.length; i++ )
        {
            var lambda = arguments[i];
            try
            {
                returnValue = lambda();
                break;
            }
            catch ( e )
            {
            }
        }

        return returnValue;
    }
}

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
    initialize: function( callback, frequency )
    {
        this.callback = callback;
        this.frequency = frequency;
        this.currentlyExecuting = false;

        this.registerCallback();
    },

    registerCallback: function()
    {
        this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
    },

    stop: function()
    {
        if ( !this.timer ) return;
        clearInterval(this.timer);
        this.timer = null;
    },

    onTimerEvent: function()
    {
        if ( !this.currentlyExecuting )
        {
            try
            {
                this.currentlyExecuting = true;
                this.callback(this);
            }
            finally
            {
                this.currentlyExecuting = false;
            }
        }
    }
}
Object.extend(String.prototype, {
    gsub: function( pattern, replacement )
    {
        var result = '', source = this, match;
        replacement = arguments.callee.prepareReplacement(replacement);

        while ( source.length > 0 )
        {
            if ( match = source.match(pattern) )
            {
                result += source.slice(0, match.index);
                result += (replacement(match) || '').toString();
                source = source.slice(match.index + match[0].length);
            }
            else
            {
                result += source,source = '';
            }
        }
        return result;
    },

    sub: function( pattern, replacement, count )
    {
        replacement = this.gsub.prepareReplacement(replacement);
        count = count === undefined ? 1 : count;

        return this.gsub(pattern, function( match )
        {
            if ( --count < 0 ) return match[0];
            return replacement(match);
        });
    },

    scan: function( pattern, iterator )
    {
        this.gsub(pattern, iterator);
        return this;
    },

    truncate: function( length, truncation )
    {
        length = length || 30;
        truncation = truncation === undefined ? '...' : truncation;
        return this.length > length ? this.slice(0, length - truncation.length) + truncation : this;
    },

    strip: function()
    {
        return this.replace(/^\s+/, '').replace(/\s+$/, '');
    },

    stripTags: function()
    {
        return this.replace(/<\/?[^>]+>/gi, '');
    },

    stripScripts: function()
    {
        return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
    },

    extractScripts: function()
    {
        var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
        var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
        return (this.match(matchAll) || []).map(function( scriptTag )
        {
            return (scriptTag.match(matchOne) || ['', ''])[1];
        });
    },

    evalScripts: function()
    {
        return this.extractScripts().map(function( script )
        {
            return eval(script)
        });
    },

    escapeHTML: function()
    {
        var div = document.createElement('div');
        var text = document.createTextNode(this);
        div.appendChild(text);
        return div.innerHTML;
    },

    unescapeHTML: function()
    {
        var div = document.createElement('div');
        div.innerHTML = this.stripTags();
        return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
    },

    toQueryParams: function()
    {
        var pairs = this.match(/^\??(.*)$/)[1].split('&');
        return pairs.inject({}, function( params, pairString )
        {
            var pair = pairString.split('=');
            var value = pair[1] ? decodeURIComponent(pair[1]) : undefined;
            params[decodeURIComponent(pair[0])] = value;
            return params;
        });
    },

    toArray: function()
    {
        return this.split('');
    },

    camelize: function()
    {
        var oStringList = this.split('-');
        if ( oStringList.length == 1 ) return oStringList[0];

        var camelizedString = this.indexOf('-') == 0 ? oStringList[0].charAt(0).toUpperCase() +
                                                       oStringList[0].substring(1) : oStringList[0];

        for ( var i = 1, len = oStringList.length; i < len; i++ )
        {
            var s = oStringList[i];
            camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
        }

        return camelizedString;
    },

    inspect: function( useDoubleQuotes )
    {
        var escapedString = this.replace(/\\/g, '\\\\');
        if ( useDoubleQuotes )
            return '"' + escapedString.replace(/"/g, '\\"') + '"';
        else
            return "'" + escapedString.replace(/'/g, '\\\'') + "'";
    }
});

String.prototype.gsub.prepareReplacement = function( replacement )
{
    if ( typeof replacement == 'function' ) return replacement;
    var template = new Template(replacement);
    return function( match )
    {
        return template.evaluate(match)
    };
}

String.prototype.parseQuery = String.prototype.toQueryParams;

var Template = Class.create();
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
Template.prototype = {
    initialize: function( template, pattern )
    {
        this.template = template.toString();
        this.pattern = pattern || Template.Pattern;
    },

    evaluate: function( object )
    {
        return this.template.gsub(this.pattern, function( match )
        {
            var before = match[1];
            if ( before == '\\' ) return match[2];
            return before + (object[match[3]] || '').toString();
        });
    }
}

var $break = new Object();
var $continue = new Object();

var Enumerable = {
    each: function( iterator )
    {
        var index = 0;
        try
        {
            this._each(function( value )
            {
                try
                {
                    iterator(value, index++);
                }
                catch ( e )
                {
                    if ( e != $continue ) throw e;
                }
            });
        }
        catch ( e )
        {
            if ( e != $break ) throw e;
        }
    },

    all: function( iterator )
    {
        var result = true;
        this.each(function( value, index )
        {
            result = result && !!(iterator || Prototype.K)(value, index);
            if ( !result ) throw $break;
        });
        return result;
    },

    any: function( iterator )
    {
        var result = false;
        this.each(function( value, index )
        {
            if ( result = !!(iterator || Prototype.K)(value, index) )
                throw $break;
        });
        return result;
    },

    collect: function( iterator )
    {
        var results = [];
        this.each(function( value, index )
        {
            results.push(iterator(value, index));
        });
        return results;
    },

    detect: function ( iterator )
    {
        var result;
        this.each(function( value, index )
        {
            if ( iterator(value, index) )
            {
                result = value;
                throw $break;
            }
        });
        return result;
    },

    findAll: function( iterator )
    {
        var results = [];
        this.each(function( value, index )
        {
            if ( iterator(value, index) )
                results.push(value);
        });
        return results;
    },

    grep: function( pattern, iterator )
    {
        var results = [];
        this.each(function( value, index )
        {
            var stringValue = value.toString();
            if ( stringValue.match(pattern) )
                results.push((iterator || Prototype.K)(value, index));
        })
        return results;
    },

    include: function( object )
    {
        var found = false;
        this.each(function( value )
        {
            if ( value == object )
            {
                found = true;
                throw $break;
            }
        });
        return found;
    },

    inject: function( memo, iterator )
    {
        this.each(function( value, index )
        {
            memo = iterator(memo, value, index);
        });
        return memo;
    },

    invoke: function( method )
    {
        var args = $A(arguments).slice(1);
        return this.collect(function( value )
        {
            return value[method].apply(value, args);
        });
    },

    max: function( iterator )
    {
        var result;
        this.each(function( value, index )
        {
            value = (iterator || Prototype.K)(value, index);
            if ( result == undefined || value >= result )
                result = value;
        });
        return result;
    },

    min: function( iterator )
    {
        var result;
        this.each(function( value, index )
        {
            value = (iterator || Prototype.K)(value, index);
            if ( result == undefined || value < result )
                result = value;
        });
        return result;
    },

    partition: function( iterator )
    {
        var trues = [], falses = [];
        this.each(function( value, index )
        {
            ((iterator || Prototype.K)(value, index) ? trues : falses).push(value);
        });
        return [trues, falses];
    },

    pluck: function( property )
    {
        var results = [];
        this.each(function( value, index )
        {
            results.push(value[property]);
        });
        return results;
    },

    reject: function( iterator )
    {
        var results = [];
        this.each(function( value, index )
        {
            if ( !iterator(value, index) )
                results.push(value);
        });
        return results;
    },

    sortBy: function( iterator )
    {
        return this.collect(function( value, index )
        {
            return {value: value, criteria: iterator(value, index)};
        }).sort(function( left, right )
        {
            var a = left.criteria, b = right.criteria;
            return a < b ? -1 : a > b ? 1 : 0;
        }).pluck('value');
    },

    toArray: function()
    {
        return this.collect(Prototype.K);
    },

    zip: function()
    {
        var iterator = Prototype.K, args = $A(arguments);
        if ( typeof args.last() == 'function' )
            iterator = args.pop();

        var collections = [this].concat(args).map($A);
        return this.map(function( value, index )
        {
            return iterator(collections.pluck(index));
        });
    },

    inspect: function()
    {
        return '#<Enumerable:' + this.toArray().inspect() + '>';
    }
}

Object.extend(Enumerable, {
    map:     Enumerable.collect,
    find:    Enumerable.detect,
    select:  Enumerable.findAll,
    member:  Enumerable.include,
    entries: Enumerable.toArray
});
var $A = Array.from = function( iterable )
{
    if ( !iterable ) return [];
    if ( iterable.toArray )
    {
        return iterable.toArray();
    }
    else
    {
        var results = [];
        for ( var i = 0; i < iterable.length; i++ )
            results.push(iterable[i]);
        return results;
    }
}

Object.extend(Array.prototype, Enumerable);

if ( !Array.prototype._reverse )
    Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
    _each: function( iterator )
    {
        for ( var i = 0; i < this.length; i++ )
            iterator(this[i]);
    },

    clear: function()
    {
        this.length = 0;
        return this;
    },

    first: function()
    {
        return this[0];
    },

    last: function()
    {
        return this[this.length - 1];
    },

    compact: function()
    {
        return this.select(function( value )
        {
            return value != undefined || value != null;
        });
    },

    flatten: function()
    {
        return this.inject([], function( array, value )
        {
            return array.concat(value && value.constructor == Array ? value.flatten() : [value]);
        });
    },

    without: function()
    {
        var values = $A(arguments);
        return this.select(function( value )
        {
            return !values.include(value);
        });
    },

    indexOf: function( object )
    {
        for ( var i = 0; i < this.length; i++ )
            if ( this[i] == object ) return i;
        return -1;
    },

    reverse: function( inline )
    {
        return (inline !== false ? this : this.toArray())._reverse();
    },

    reduce: function()
    {
        return this.length > 1 ? this : this[0];
    },

    uniq: function()
    {
        return this.inject([], function( array, value )
        {
            return array.include(value) ? array : array.concat([value]);
        });
    },

    inspect: function()
    {
        return '[' + this.map(Object.inspect).join(', ') + ']';
    }
});
var Hash = {
    _each: function( iterator )
    {
        for ( var key in this )
        {
            var value = this[key];
            if ( typeof value == 'function' ) continue;

            var pair = [key, value];
            pair.key = key;
            pair.value = value;
            iterator(pair);
        }
    },

    keys: function()
    {
        return this.pluck('key');
    },

    values: function()
    {
        return this.pluck('value');
    },

    merge: function( hash )
    {
        return $H(hash).inject($H(this), function( mergedHash, pair )
        {
            mergedHash[pair.key] = pair.value;
            return mergedHash;
        });
    },

    toQueryString: function()
    {
        return this.map(function( pair )
        {
            return pair.map(encodeURIComponent).join('=');
        }).join('&');
    },

    inspect: function()
    {
        return '#<Hash:{' + this.map(function( pair )
        {
            return pair.map(Object.inspect).join(': ');
        }).join(', ') + '}>';
    }
}

function $H( object )
{
    var hash = Object.extend({}, object || {});
    Object.extend(hash, Enumerable);
    Object.extend(hash, Hash);
    return hash;
}
ObjectRange = Class.create();
Object.extend(ObjectRange.prototype, Enumerable);
Object.extend(ObjectRange.prototype, {
    initialize: function( start, end, exclusive )
    {
        this.start = start;
        this.end = end;
        this.exclusive = exclusive;
    },

    _each: function( iterator )
    {
        var value = this.start;
        while ( this.include(value) )
        {
            iterator(value);
            value = value.succ();
        }
    },

    include: function( value )
    {
        if ( value < this.start )
            return false;
        if ( this.exclusive )
            return value < this.end;
        return value <= this.end;
    }
});

var $R = function( start, end, exclusive )
{
    return new ObjectRange(start, end, exclusive);
}

var Ajax = {
    getTransport: function()
    {
        return Try.these(function()
        {
            return new XMLHttpRequest()
        }, function()
        {
            return new ActiveXObject('Msxml2.XMLHTTP')
        }, function()
        {
            return new ActiveXObject('Microsoft.XMLHTTP')
        }) || false;
    },

    activeRequestCount: 0
}

Ajax.Responders = {
    responders: [],

    _each: function( iterator )
    {
        this.responders._each(iterator);
    },

    register: function( responderToAdd )
    {
        if ( !this.include(responderToAdd) )
            this.responders.push(responderToAdd);
    },

    unregister: function( responderToRemove )
    {
        this.responders = this.responders.without(responderToRemove);
    },

    dispatch: function( callback, request, transport, json )
    {
        this.each(function( responder )
        {
            if ( responder[callback] && typeof responder[callback] == 'function' )
            {
                try
                {
                    responder[callback].apply(responder, [request, transport, json]);
                }
                catch ( e )
                {
                }
            }
        });
    }
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
    onCreate: function()
    {
        Ajax.activeRequestCount++;
    },

    onComplete: function()
    {
        Ajax.activeRequestCount--;
    }
});

Ajax.Base = function()
{
};
Ajax.Base.prototype = {
    setOptions: function( options )
    {
        this.options = {
            method:       'post',
            asynchronous: true,
            contentType:  'application/x-www-form-urlencoded',
            parameters:   ''
        }
        Object.extend(this.options, options || {});
    },

    responseIsSuccess: function()
    {
        return this.transport.status == undefined || this.transport.status == 0 ||
               (this.transport.status >= 200 && this.transport.status < 300);
    },

    responseIsFailure: function()
    {
        return !this.responseIsSuccess();
    }
}

Ajax.Request = Class.create();
Ajax.Request.Events = ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
    initialize: function( url, options )
    {
        this.transport = Ajax.getTransport();
        this.setOptions(options);
        this.request(url);
    },

    request: function( url )
    {
        var parameters = this.options.parameters || '';
        if ( parameters.length > 0 ) parameters += '&_=';

        /* Simulate other verbs over post */
        if ( this.options.method != 'get' && this.options.method != 'post' )
        {
            parameters += (parameters.length > 0 ? '&' : '') + '_method=' + this.options.method;
            this.options.method = 'post';
        }

        try
        {
            this.url = url;
            if ( this.options.method == 'get' && parameters.length > 0 )
                this.url += (this.url.match(/\?/) ? '&' : '?') + parameters;

            Ajax.Responders.dispatch('onCreate', this, this.transport);

            this.transport.open(this.options.method, this.url, this.options.asynchronous);

            if ( this.options.asynchronous )
                setTimeout(function()
                {
                    this.respondToReadyState(1)
                }.bind(this), 10);

            this.transport.onreadystatechange = this.onStateChange.bind(this);
            this.setRequestHeaders();

            var body = this.options.postBody ? this.options.postBody : parameters;
            this.transport.send(this.options.method == 'post' ? body : null);

            /* Force Firefox to handle ready state 4 for synchronous requests */
            if ( !this.options.asynchronous && this.transport.overrideMimeType )
                this.onStateChange();

        }
        catch ( e )
        {
            this.dispatchException(e);
        }
    },

    setRequestHeaders: function()
    {
        var requestHeaders = ['X-Requested-With', 'XMLHttpRequest',
            'X-Prototype-Version', Prototype.Version,
            'Accept', 'text/javascript, text/html, application/xml, text/xml, */*'];

        if ( this.options.method == 'post' )
        {
            requestHeaders.push('Content-type', this.options.contentType);

            /* Force "Connection: close" for Mozilla browsers to work around
            * a bug where XMLHttpReqeuest sends an incorrect Content-length
            * header. See Mozilla Bugzilla #246651.
            */
            if ( this.transport.overrideMimeType )
                requestHeaders.push('Connection', 'close');
        }

        if ( this.options.requestHeaders )
            requestHeaders.push.apply(requestHeaders, this.options.requestHeaders);

        for ( var i = 0; i < requestHeaders.length; i += 2 )
            this.transport.setRequestHeader(requestHeaders[i], requestHeaders[i + 1]);
    },

    onStateChange: function()
    {
        var readyState = this.transport.readyState;
        if ( readyState != 1 )
            this.respondToReadyState(this.transport.readyState);
    },

    header: function( name )
    {
        try
        {
            return this.transport.getResponseHeader(name);
        }
        catch ( e )
        {
        }
    },

    evalJSON: function()
    {
        try
        {
            return eval('(' + this.header('X-JSON') + ')');
        }
        catch ( e )
        {
        }
    },

    evalResponse: function()
    {
        try
        {
            return eval(this.transport.responseText);
        }
        catch ( e )
        {
            this.dispatchException(e);
        }
    },

    respondToReadyState: function( readyState )
    {
        var event = Ajax.Request.Events[readyState];
        var transport = this.transport, json = this.evalJSON();

        if ( event == 'Complete' )
        {
            try
            {
                (this.options['on' + this.transport.status] ||
                 this.options['on' + (this.responseIsSuccess() ? 'Success' : 'Failure')] ||
                 Prototype.emptyFunction)(transport, json);
            }
            catch ( e )
            {
                this.dispatchException(e);
            }

            if ( (this.header('Content-type') || '').match(/^text\/javascript/i) )
                this.evalResponse();
        }

        try
        {
            (this.options['on' + event] || Prototype.emptyFunction)(transport, json);
            Ajax.Responders.dispatch('on' + event, this, transport, json);
        }
        catch ( e )
        {
            this.dispatchException(e);
        }

        /* Avoid memory leak in MSIE: clean up the oncomplete event handler */
        if ( event == 'Complete' )
            this.transport.onreadystatechange = Prototype.emptyFunction;
    },

    dispatchException: function( exception )
    {
        (this.options.onException || Prototype.emptyFunction)(this, exception);
        Ajax.Responders.dispatch('onException', this, exception);
    }
});

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
    initialize: function( container, url, options )
    {
        this.containers = {
            success: container.success ? $(container.success) : $(container),
            failure: container.failure ? $(container.failure) : (container.success ? null : $(container))
        }

        this.transport = Ajax.getTransport();
        this.setOptions(options);

        var onComplete = this.options.onComplete || Prototype.emptyFunction;
        this.options.onComplete = (function( transport, object )
        {
            this.updateContent();
            onComplete(transport, object);
        }).bind(this);

        this.request(url);
    },

    updateContent: function()
    {
        var receiver = this.responseIsSuccess() ? this.containers.success : this.containers.failure;
        var response = this.transport.responseText;

        if ( !this.options.evalScripts )
            response = response.stripScripts();

        if ( receiver )
        {
            if ( this.options.insertion )
            {
                new this.options.insertion(receiver, response);
            }
            else
            {
                Element.update(receiver, response);
            }
        }

        if ( this.responseIsSuccess() )
        {
            if ( this.onComplete )
                setTimeout(this.onComplete.bind(this), 10);
        }
    }
});

Ajax.PeriodicalUpdater = Class.create();
Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
    initialize: function( container, url, options )
    {
        this.setOptions(options);
        this.onComplete = this.options.onComplete;

        this.frequency = (this.options.frequency || 2);
        this.decay = (this.options.decay || 1);

        this.updater = {};
        this.container = container;
        this.url = url;

        this.start();
    },

    start: function()
    {
        this.options.onComplete = this.updateComplete.bind(this);
        this.onTimerEvent();
    },

    stop: function()
    {
        this.updater.options.onComplete = undefined;
        clearTimeout(this.timer);
        (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
    },

    updateComplete: function( request )
    {
        if ( this.options.decay )
        {
            this.decay = (request.responseText == this.lastText ? this.decay * this.options.decay : 1);

            this.lastText = request.responseText;
        }
        this.timer = setTimeout(this.onTimerEvent.bind(this), this.decay * this.frequency * 1000);
    },

    onTimerEvent: function()
    {
        this.updater = new Ajax.Updater(this.container, this.url, this.options);
    }
});
function $()
{
    var results = [], element;
    for ( var i = 0; i < arguments.length; i++ )
    {
        element = arguments[i];
        if ( typeof element == 'string' )
            element = document.getElementById(element);
        results.push(Element.extend(element));
    }
    return results.reduce();
}

document.getElementsByClassName = function( className, parentElement )
{
    var children = ($(parentElement) || document.body).getElementsByTagName('*');
    return $A(children).inject([], function( elements, child )
    {
        if ( child.className.match(new RegExp("(^|\\s)" + className + "(\\s|$)")) )
            elements.push(Element.extend(child));
        return elements;
    });
}

/*--------------------------------------------------------------------------*/

if ( !window.Element )
    var Element = new Object();

Element.extend = function( element )
{
    if ( !element ) return;
    if ( _nativeExtensions || element.nodeType == 3 ) return element;

    if ( !element._extended && element.tagName && element != window )
    {
        var methods = Object.clone(Element.Methods), cache = Element.extend.cache;

        if ( element.tagName == 'FORM' )
            Object.extend(methods, Form.Methods);
        if ( ['INPUT', 'TEXTAREA', 'SELECT'].include(element.tagName) )
            Object.extend(methods, Form.Element.Methods);

        for ( var property in methods )
        {
            var value = methods[property];
            if ( typeof value == 'function' )
                element[property] = cache.findOrStore(value);
        }
    }

    element._extended = true;
    return element;
}

Element.extend.cache = {
    findOrStore: function( value )
    {
        return this[value] = this[value] || function()
        {
            return value.apply(null, [this].concat($A(arguments)));
        }
    }
}

Element.Methods = {
    visible: function( element )
    {
        return $(element).style.display != 'none';
    },

    toggle: function( element )
    {
        element = $(element);
        Element[Element.visible(element) ? 'hide' : 'show'](element);
        return element;
    },

    hide: function( element )
    {
        $(element).style.display = 'none';
        return element;
    },

    show: function( element )
    {
        $(element).style.display = '';
        return element;
    },

    remove: function( element )
    {
        element = $(element);
        element.parentNode.removeChild(element);
        return element;
    },

    update: function( element, html )
    {
        $(element).innerHTML = html.stripScripts();
        setTimeout(function()
        {
            html.evalScripts()
        }, 10);
        return element;
    },

    replace: function( element, html )
    {
        element = $(element);
        if ( element.outerHTML )
        {
            element.outerHTML = html.stripScripts();
        }
        else
        {
            var range = element.ownerDocument.createRange();
            range.selectNodeContents(element);
            element.parentNode.replaceChild(range.createContextualFragment(html.stripScripts()), element);
        }
        setTimeout(function()
        {
            html.evalScripts()
        }, 10);
        return element;
    },

    inspect: function( element )
    {
        element = $(element);
        var result = '<' + element.tagName.toLowerCase();
        $H({'id': 'id', 'className': 'class'}).each(function( pair )
        {
            var property = pair.first(), attribute = pair.last();
            var value = (element[property] || '').toString();
            if ( value ) result += ' ' + attribute + '=' + value.inspect(true);
        });
        return result + '>';
    },

    recursivelyCollect: function( element, property )
    {
        element = $(element);
        var elements = [];
        while ( element = element[property] )
            if ( element.nodeType == 1 )
                elements.push(Element.extend(element));
        return elements;
    },

    ancestors: function( element )
    {
        return $(element).recursivelyCollect('parentNode');
    },

    descendants: function( element )
    {
        element = $(element);
        return $A(element.getElementsByTagName('*'));
    },

    previousSiblings: function( element )
    {
        return $(element).recursivelyCollect('previousSibling');
    },

    nextSiblings: function( element )
    {
        return $(element).recursivelyCollect('nextSibling');
    },

    siblings: function( element )
    {
        element = $(element);
        return element.previousSiblings().reverse().concat(element.nextSiblings());
    },

    match: function( element, selector )
    {
        element = $(element);
        if ( typeof selector == 'string' )
            selector = new Selector(selector);
        return selector.match(element);
    },

    up: function( element, expression, index )
    {
        return Selector.findElement($(element).ancestors(), expression, index);
    },

    down: function( element, expression, index )
    {
        return Selector.findElement($(element).descendants(), expression, index);
    },

    previous: function( element, expression, index )
    {
        return Selector.findElement($(element).previousSiblings(), expression, index);
    },

    next: function( element, expression, index )
    {
        return Selector.findElement($(element).nextSiblings(), expression, index);
    },

    getElementsBySelector: function()
    {
        var args = $A(arguments), element = $(args.shift());
        return Selector.findChildElements(element, args);
    },

    getElementsByClassName: function( element, className )
    {
        element = $(element);
        return document.getElementsByClassName(className, element);
    },

    getHeight: function( element )
    {
        element = $(element);
        return element.offsetHeight;
    },

    classNames: function( element )
    {
        return new Element.ClassNames(element);
    },

    hasClassName: function( element, className )
    {
        if ( !(element = $(element)) ) return;
        return Element.classNames(element).include(className);
    },

    addClassName: function( element, className )
    {
        if ( !(element = $(element)) ) return;
        Element.classNames(element).add(className);
        return element;
    },

    removeClassName: function( element, className )
    {
        if ( !(element = $(element)) ) return;
        Element.classNames(element).remove(className);
        return element;
    },

    observe: function()
    {
        Event.observe.apply(Event, arguments);
        return $A(arguments).first();
    },

    stopObserving: function()
    {
        Event.stopObserving.apply(Event, arguments);
        return $A(arguments).first();
    },

// removes whitespace-only text node children
    cleanWhitespace: function( element )
    {
        element = $(element);
        var node = element.firstChild;
        while ( node )
        {
            var nextNode = node.nextSibling;
            if ( node.nodeType == 3 && !/\S/.test(node.nodeValue) )
                element.removeChild(node);
            node = nextNode;
        }
        return element;
    },

    empty: function( element )
    {
        return $(element).innerHTML.match(/^\s*$/);
    },

    childOf: function( element, ancestor )
    {
        element = $(element),ancestor = $(ancestor);
        while ( element = element.parentNode )
            if ( element == ancestor ) return true;
        return false;
    },

    scrollTo: function( element )
    {
        element = $(element);
        var x = element.x ? element.x : element.offsetLeft,
            y = element.y ? element.y : element.offsetTop;
        window.scrollTo(x, y);
        return element;
    },

    getStyle: function( element, style )
    {
        element = $(element);
        var value = element.style[style.camelize()];
        if ( !value )
        {
            if ( document.defaultView && document.defaultView.getComputedStyle )
            {
                var css = document.defaultView.getComputedStyle(element, null);
                value = css ? css.getPropertyValue(style) : null;
            }
            else if ( element.currentStyle )
            {
                value = element.currentStyle[style.camelize()];
            }
        }

        if ( window.opera && ['left', 'top', 'right', 'bottom'].include(style) )
            if ( Element.getStyle(element, 'position') == 'static' ) value = 'auto';

        return value == 'auto' ? null : value;
    },

    setStyle: function( element, style )
    {
        element = $(element);
        for ( var name in style )
            element.style[name.camelize()] = style[name];
        return element;
    },

    getDimensions: function( element )
    {
        element = $(element);
        if ( Element.getStyle(element, 'display') != 'none' )
            return {width: element.offsetWidth, height: element.offsetHeight};

        // All *Width and *Height properties give 0 on elements with display none,
        // so enable the element temporarily
        var els = element.style;
        var originalVisibility = els.visibility;
        var originalPosition = els.position;
        els.visibility = 'hidden';
        els.position = 'absolute';
        els.display = '';
        var originalWidth = element.clientWidth;
        var originalHeight = element.clientHeight;
        els.display = 'none';
        els.position = originalPosition;
        els.visibility = originalVisibility;
        return {width: originalWidth, height: originalHeight};
    },

    makePositioned: function( element )
    {
        element = $(element);
        var pos = Element.getStyle(element, 'position');
        if ( pos == 'static' || !pos )
        {
            element._madePositioned = true;
            element.style.position = 'relative';
            // Opera returns the offset relative to the positioning context, when an
            // element is position relative but top and left have not been defined
            if ( window.opera )
            {
                element.style.top = 0;
                element.style.left = 0;
            }
        }
        return element;
    },

    undoPositioned: function( element )
    {
        element = $(element);
        if ( element._madePositioned )
        {
            element._madePositioned = undefined;
            element.style.position =
            element.style.top = element.style.left = element.style.bottom = element.style.right = '';
        }
        return element;
    },

    makeClipping: function( element )
    {
        element = $(element);
        if ( element._overflow ) return;
        element._overflow = element.style.overflow || 'auto';
        if ( (Element.getStyle(element, 'overflow') || 'visible') != 'hidden' )
            element.style.overflow = 'hidden';
        return element;
    },

    undoClipping: function( element )
    {
        element = $(element);
        if ( !element._overflow ) return;
        element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
        element._overflow = null;
        return element;
    }
}

// IE is missing .innerHTML support for TABLE-related elements
if ( document.all )
{
    Element.Methods.update = function( element, html )
    {
        element = $(element);
        var tagName = element.tagName.toUpperCase();
        if ( ['THEAD','TBODY','TR','TD'].indexOf(tagName) > -1 )
        {
            var div = document.createElement('div');
            switch ( tagName )
                {
                case 'THEAD':
                case 'TBODY':
                    div.innerHTML = '<table><tbody>' + html.stripScripts() + '</tbody></table>';
                    depth = 2;
                    break;
                case 'TR':
                    div.innerHTML = '<table><tbody><tr>' + html.stripScripts() + '</tr></tbody></table>';
                    depth = 3;
                    break;
                case 'TD':
                    div.innerHTML = '<table><tbody><tr><td>' + html.stripScripts() + '</td></tr></tbody></table>';
                    depth = 4;
            }
            $A(element.childNodes).each(function( node )
            {
                element.removeChild(node)
            });
            depth.times(function()
            {
                div = div.firstChild
            });

            $A(div.childNodes).each(function( node )
            {
                element.appendChild(node)
            });
        }
        else
        {
            element.innerHTML = html.stripScripts();
        }
        setTimeout(function()
        {
            html.evalScripts()
        }, 10);
        return element;
    }
}

Object.extend(Element, Element.Methods);

var _nativeExtensions = false;

if ( !window.HTMLElement && /Konqueror|Safari|KHTML/.test(navigator.userAgent) )
{
    /* Emulate HTMLElement, HTMLFormElement, HTMLInputElement, HTMLTextAreaElement,
and HTMLSelectElement in Safari */
    ['', 'Form', 'Input', 'TextArea', 'Select'].each(function( tag )
    {
        var klass = window['HTML' + tag + 'Element'] = {};
        klass.prototype = document.createElement(tag ? tag.toLowerCase() : 'div').__proto__;
    });
}

Element.addMethods = function( methods )
{
    Object.extend(Element.Methods, methods || {});

    function copy( methods, destination )
    {
        var cache = Element.extend.cache;
        for ( var property in methods )
        {
            var value = methods[property];
            destination[property] = cache.findOrStore(value);
        }
    }

    if ( typeof HTMLElement != 'undefined' )
    {
        copy(Element.Methods, HTMLElement.prototype);
        copy(Form.Methods, HTMLFormElement.prototype);
        [HTMLInputElement, HTMLTextAreaElement, HTMLSelectElement].each(function( klass )
        {
            copy(Form.Element.Methods, klass.prototype);
        });
        _nativeExtensions = true;
    }
}

var Toggle = new Object();
Toggle.display = Element.toggle;

/*--------------------------------------------------------------------------*/

Abstract.Insertion = function( adjacency )
{
    this.adjacency = adjacency;
}

Abstract.Insertion.prototype = {
    initialize: function( element, content )
    {
        this.element = $(element);
        this.content = content.stripScripts();

        if ( this.adjacency && this.element.insertAdjacentHTML )
        {
            try
            {
                this.element.insertAdjacentHTML(this.adjacency, this.content);
            }
            catch ( e )
            {
                var tagName = this.element.tagName.toLowerCase();
                if ( tagName == 'tbody' || tagName == 'tr' )
                {
                    this.insertContent(this.contentFromAnonymousTable());
                }
                else
                {
                    throw e;
                }
            }
        }
        else
        {
            this.range = this.element.ownerDocument.createRange();
            if ( this.initializeRange ) this.initializeRange();
            this.insertContent([this.range.createContextualFragment(this.content)]);
        }

        setTimeout(function()
        {
            content.evalScripts()
        }, 10);
    },

    contentFromAnonymousTable: function()
    {
        var div = document.createElement('div');
        div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
        return $A(div.childNodes[0].childNodes[0].childNodes);
    }
}

var Insertion = new Object();

Insertion.Before = Class.create();
Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
    initializeRange: function()
    {
        this.range.setStartBefore(this.element);
    },

    insertContent: function( fragments )
    {
        fragments.each((function( fragment )
        {
            this.element.parentNode.insertBefore(fragment, this.element);
        }).bind(this));
    }
});

Insertion.Top = Class.create();
Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
    initializeRange: function()
    {
        this.range.selectNodeContents(this.element);
        this.range.collapse(true);
    },

    insertContent: function( fragments )
    {
        fragments.reverse(false).each((function( fragment )
        {
            this.element.insertBefore(fragment, this.element.firstChild);
        }).bind(this));
    }
});

Insertion.Bottom = Class.create();
Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
    initializeRange: function()
    {
        this.range.selectNodeContents(this.element);
        this.range.collapse(this.element);
    },

    insertContent: function( fragments )
    {
        fragments.each((function( fragment )
        {
            this.element.appendChild(fragment);
        }).bind(this));
    }
});

Insertion.After = Class.create();
Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
    initializeRange: function()
    {
        this.range.setStartAfter(this.element);
    },

    insertContent: function( fragments )
    {
        fragments.each((function( fragment )
        {
            this.element.parentNode.insertBefore(fragment, this.element.nextSibling);
        }).bind(this));
    }
});

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
    initialize: function( element )
    {
        this.element = $(element);
    },

    _each: function( iterator )
    {
        this.element.className.split(/\s+/).select(function( name )
        {
            return name.length > 0;
        })._each(iterator);
    },

    set: function( className )
    {
        this.element.className = className;
    },

    add: function( classNameToAdd )
    {
        if ( this.include(classNameToAdd) ) return;
        this.set(this.toArray().concat(classNameToAdd).join(' '));
    },

    remove: function( classNameToRemove )
    {
        if ( !this.include(classNameToRemove) ) return;
        this.set(this.select(function( className )
        {
            return className != classNameToRemove;
        }).join(' '));
    },

    toString: function()
    {
        return this.toArray().join(' ');
    }
}

Object.extend(Element.ClassNames.prototype, Enumerable);
var Selector = Class.create();
Selector.prototype = {
    initialize: function( expression )
    {
        this.params = {classNames: []};
        this.expression = expression.toString().strip();
        this.parseExpression();
        this.compileMatcher();
    },

    parseExpression: function()
    {
        function abort( message )
        {
            throw 'Parse error in selector: ' + message;
        }

        if ( this.expression == '' )  abort('empty expression');

        var params = this.params, expr = this.expression, match, modifier, clause, rest;
        while ( match = expr.match(/^(.*)\[([a-z0-9_:-]+?)(?:([~\|!]?=)(?:"([^"]*)"|([^\]\s]*)))?\]$/i) )
        {
            params.attributes = params.attributes || [];
            params.attributes.push({name: match[2], operator: match[3], value: match[4] || match[5] || ''});
            expr = match[1];
        }

        if ( expr == '*' ) return this.params.wildcard = true;

        while ( match = expr.match(/^([^a-z0-9_-])?([a-z0-9_-]+)(.*)/i) )
        {
            modifier = match[1],clause = match[2],rest = match[3];
            switch ( modifier )
                {
                case '#':       params.id = clause; break;
                case '.':       params.classNames.push(clause); break;
                case '':
                case undefined: params.tagName = clause.toUpperCase(); break;
                default:        abort(expr.inspect());
            }
            expr = rest;
        }

        if ( expr.length > 0 ) abort(expr.inspect());
    },

    buildMatchExpression: function()
    {
        var params = this.params, conditions = [], clause;

        if ( params.wildcard )
            conditions.push('true');
        if ( clause = params.id )
            conditions.push('element.id == ' + clause.inspect());
        if ( clause = params.tagName )
            conditions.push('element.tagName.toUpperCase() == ' + clause.inspect());
        if ( (clause = params.classNames).length > 0 )
            for ( var i = 0; i < clause.length; i++ )
                conditions.push('Element.hasClassName(element, ' + clause[i].inspect() + ')');
        if ( clause = params.attributes )
        {
            clause.each(function( attribute )
            {
                var value = 'element.getAttribute(' + attribute.name.inspect() + ')';
                var splitValueBy = function( delimiter )
                {
                    return value + ' && ' + value + '.split(' + delimiter.inspect() + ')';
                }

                switch ( attribute.operator )
                    {
                    case '=':       conditions.push(value + ' == ' + attribute.value.inspect()); break;
                    case '~=':      conditions.push(splitValueBy(' ') + '.include(' + attribute.value.inspect() +
                                                    ')'); break;
                    case '|=':      conditions.push(splitValueBy('-') + '.first().toUpperCase() == ' +
                                                    attribute.value.toUpperCase().inspect()); break;
                    case '!=':      conditions.push(value + ' != ' + attribute.value.inspect()); break;
                    case '':
                    case undefined: conditions.push(value + ' != null'); break;
                    default:        throw 'Unknown operator ' + attribute.operator + ' in selector';
                }
            });
        }

        return conditions.join(' && ');
    },

    compileMatcher: function()
    {
        this.match = new Function('element', 'if (!element.tagName) return false; \
        return ' + this.buildMatchExpression());
    },

    findElements: function( scope )
    {
        var element;

        if ( element = $(this.params.id) )
            if ( this.match(element) )
                if ( !scope || Element.childOf(element, scope) )
                    return [element];

        scope = (scope || document).getElementsByTagName(this.params.tagName || '*');

        var results = [];
        for ( var i = 0; i < scope.length; i++ )
            if ( this.match(element = scope[i]) )
                results.push(Element.extend(element));

        return results;
    },

    toString: function()
    {
        return this.expression;
    }
}

Object.extend(Selector, {
    matchElements: function( elements, expression )
    {
        var selector = new Selector(expression);
        return elements.select(selector.match.bind(selector));
    },

    findElement: function( elements, expression, index )
    {
        if ( typeof expression == 'number' ) index = expression,expression = false;
        return Selector.matchElements(elements, expression || '*')[index || 0];
    },

    findChildElements: function( element, expressions )
    {
        return expressions.map(function( expression )
        {
            return expression.strip().split(/\s+/).inject([null], function( results, expr )
            {
                var selector = new Selector(expr);
                return results.inject([], function( elements, result )
                {
                    return elements.concat(selector.findElements(result || element));
                });
            });
        }).flatten();
    }
});

function $$()
{
    return Selector.findChildElements(document, $A(arguments));
}
var Form = {
    reset: function( form )
    {
        $(form).reset();
        return form;
    }
};

Form.Methods = {
    serialize: function( form )
    {
        var elements = Form.getElements($(form));
        var queryComponents = new Array();

        for ( var i = 0; i < elements.length; i++ )
        {
            var queryComponent = Form.Element.serialize(elements[i]);
            if ( queryComponent )
                queryComponents.push(queryComponent);
        }

        return queryComponents.join('&');
    },

    getElements: function( form )
    {
        form = $(form);
        var elements = new Array();

        for ( var tagName in Form.Element.Serializers )
        {
            var tagElements = form.getElementsByTagName(tagName);
            for ( var j = 0; j < tagElements.length; j++ )
                elements.push(tagElements[j]);
        }
        return elements;
    },

    getInputs: function( form, typeName, name )
    {
        form = $(form);
        var inputs = form.getElementsByTagName('input');

        if ( !typeName && !name )
            return inputs;

        var matchingInputs = new Array();
        for ( var i = 0; i < inputs.length; i++ )
        {
            var input = inputs[i];
            if ( (typeName && input.type != typeName) || (name && input.name != name) )
                continue;
            matchingInputs.push(input);
        }

        return matchingInputs;
    },

    disable: function( form )
    {
        form = $(form);
        var elements = Form.getElements(form);
        for ( var i = 0; i < elements.length; i++ )
        {
            var element = elements[i];
            element.blur();
            element.disabled = 'true';
        }
        return form;
    },

    enable: function( form )
    {
        form = $(form);
        var elements = Form.getElements(form);
        for ( var i = 0; i < elements.length; i++ )
        {
            var element = elements[i];
            element.disabled = '';
        }
        return form;
    },

    findFirstElement: function( form )
    {
        return Form.getElements(form).find(function( element )
        {
            return element.type != 'hidden' && !element.disabled &&
                   ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
        });
    },

    focusFirstElement: function( form )
    {
        form = $(form);
        Field.activate(Form.findFirstElement(form));
        return form;
    }
}

Object.extend(Form, Form.Methods);

/*--------------------------------------------------------------------------*/

Form.Element = {
    focus: function( element )
    {
        $(element).focus();
        return element;
    },

    select: function( element )
    {
        $(element).select();
        return element;
    }
}

Form.Element.Methods = {
    serialize: function( element )
    {
        element = $(element);
        var method = element.tagName.toLowerCase();
        var parameter = Form.Element.Serializers[method](element);

        if ( parameter )
        {
            var key = encodeURIComponent(parameter[0]);
            if ( key.length == 0 ) return;

            if ( parameter[1].constructor != Array )
                parameter[1] = [parameter[1]];

            return parameter[1].map(function( value )
            {
                return key + '=' + encodeURIComponent(value);
            }).join('&');
        }
    },

    getValue: function( element )
    {
        element = $(element);
        var method = element.tagName.toLowerCase();
        var parameter = Form.Element.Serializers[method](element);

        if ( parameter )
            return parameter[1];
    },

    clear: function( element )
    {
        $(element).value = '';
        return element;
    },

    present: function( element )
    {
        return $(element).value != '';
    },

    activate: function( element )
    {
        element = $(element);
        element.focus();
        if ( element.select )
            element.select();
        return element;
    },

    disable: function( element )
    {
        element = $(element);
        element.disabled = '';
        return element;
    },

    enable: function( element )
    {
        element = $(element);
        element.blur();
        element.disabled = 'true';
        return element;
    }
}

Object.extend(Form.Element, Form.Element.Methods);
var Field = Form.Element;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
    input: function( element )
    {
        switch ( element.type.toLowerCase() )
            {
            case 'checkbox':
            case 'radio':
                return Form.Element.Serializers.inputSelector(element);
            default:
                return Form.Element.Serializers.textarea(element);
        }
        return false;
    },

    inputSelector: function( element )
    {
        if ( element.checked )
            return [element.name, element.value];
    },

    textarea: function( element )
    {
        return [element.name, element.value];
    },

    select: function( element )
    {
        return Form.Element.Serializers[element.type == 'select-one' ? 'selectOne' : 'selectMany'](element);
    },

    selectOne: function( element )
    {
        var value = '', opt, index = element.selectedIndex;
        if ( index >= 0 )
        {
            opt = element.options[index];
            value = opt.value || opt.text;
        }
        return [element.name, value];
    },

    selectMany: function( element )
    {
        var value = [];
        for ( var i = 0; i < element.length; i++ )
        {
            var opt = element.options[i];
            if ( opt.selected )
                value.push(opt.value || opt.text);
        }
        return [element.name, value];
    }
}

/*--------------------------------------------------------------------------*/

var $F = Form.Element.getValue;

/*--------------------------------------------------------------------------*/

Abstract.TimedObserver = function()
{
}
Abstract.TimedObserver.prototype = {
    initialize: function( element, frequency, callback )
    {
        this.frequency = frequency;
        this.element = $(element);
        this.callback = callback;

        this.lastValue = this.getValue();
        this.registerCallback();
    },

    registerCallback: function()
    {
        setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
    },

    onTimerEvent: function()
    {
        var value = this.getValue();
        if ( this.lastValue != value )
        {
            this.callback(this.element, value);
            this.lastValue = value;
        }
    }
}

Form.Element.Observer = Class.create();
Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
    getValue: function()
    {
        return Form.Element.getValue(this.element);
    }
});

Form.Observer = Class.create();
Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
    getValue: function()
    {
        return Form.serialize(this.element);
    }
});

/*--------------------------------------------------------------------------*/

Abstract.EventObserver = function()
{
}
Abstract.EventObserver.prototype = {
    initialize: function( element, callback )
    {
        this.element = $(element);
        this.callback = callback;

        this.lastValue = this.getValue();
        if ( this.element.tagName.toLowerCase() == 'form' )
            this.registerFormCallbacks();
        else
            this.registerCallback(this.element);
    },

    onElementEvent: function()
    {
        var value = this.getValue();
        if ( this.lastValue != value )
        {
            this.callback(this.element, value);
            this.lastValue = value;
        }
    },

    registerFormCallbacks: function()
    {
        var elements = Form.getElements(this.element);
        for ( var i = 0; i < elements.length; i++ )
            this.registerCallback(elements[i]);
    },

    registerCallback: function( element )
    {
        if ( element.type )
        {
            switch ( element.type.toLowerCase() )
                {
                case 'checkbox':
                case 'radio':
                    Event.observe(element, 'click', this.onElementEvent.bind(this));
                    break;
                default:
                    Event.observe(element, 'change', this.onElementEvent.bind(this));
                    break;
            }
        }
    }
}

Form.Element.EventObserver = Class.create();
Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
    getValue: function()
    {
        return Form.Element.getValue(this.element);
    }
});

Form.EventObserver = Class.create();
Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
    getValue: function()
    {
        return Form.serialize(this.element);
    }
});
if ( !window.Event )
{
    var Event = new Object();
}

Object.extend(Event, {
    KEY_BACKSPACE: 8,
    KEY_TAB:       9,
    KEY_RETURN:   13,
    KEY_ESC:      27,
    KEY_LEFT:     37,
    KEY_UP:       38,
    KEY_RIGHT:    39,
    KEY_DOWN:     40,
    KEY_DELETE:   46,
    KEY_HOME:     36,
    KEY_END:      35,
    KEY_PAGEUP:   33,
    KEY_PAGEDOWN: 34,

    element: function( event )
    {
        return event.target || event.srcElement;
    },

    isLeftClick: function( event )
    {
        return (((event.which) && (event.which == 1)) || ((event.button) && (event.button == 1)));
    },

    pointerX: function( event )
    {
        return event.pageX || (event.clientX + (document.documentElement.scrollLeft || document.body.scrollLeft));
    },

    pointerY: function( event )
    {
        return event.pageY || (event.clientY + (document.documentElement.scrollTop || document.body.scrollTop));
    },

    stop: function( event )
    {
        if ( event.preventDefault )
        {
            event.preventDefault();
            event.stopPropagation();
        }
        else
        {
            event.returnValue = false;
            event.cancelBubble = true;
        }
    },

// find the first node with the given tagName, starting from the
// node the event was triggered on; traverses the DOM upwards
    findElement: function( event, tagName )
    {
        var element = Event.element(event);
        while ( element.parentNode && (!element.tagName || (element.tagName.toUpperCase() != tagName.toUpperCase())) )
            element = element.parentNode;
        return element;
    },

    observers: false,

    _observeAndCache: function( element, name, observer, useCapture )
    {
        if ( !this.observers ) this.observers = [];
        if ( element.addEventListener )
        {
            this.observers.push([element, name, observer, useCapture]);
            element.addEventListener(name, observer, useCapture);
        }
        else if ( element.attachEvent )
        {
            this.observers.push([element, name, observer, useCapture]);
            element.attachEvent('on' + name, observer);
        }
    },

    unloadCache: function()
    {
        if ( !Event.observers ) return;
        for ( var i = 0; i < Event.observers.length; i++ )
        {
            Event.stopObserving.apply(this, Event.observers[i]);
            Event.observers[i][0] = null;
        }
        Event.observers = false;
    },

    observe: function( element, name, observer, useCapture )
    {
        element = $(element);
        useCapture = useCapture || false;

        if ( name == 'keypress' && (navigator.appVersion.match(/Konqueror|Safari|KHTML/) || element.attachEvent) )
            name = 'keydown';

        Event._observeAndCache(element, name, observer, useCapture);
    },

    stopObserving: function( element, name, observer, useCapture )
    {
        element = $(element);
        useCapture = useCapture || false;

        if ( name == 'keypress' && (navigator.appVersion.match(/Konqueror|Safari|KHTML/) || element.detachEvent) )
            name = 'keydown';

        if ( element.removeEventListener )
        {
            element.removeEventListener(name, observer, useCapture);
        }
        else if ( element.detachEvent )
        {
            try
            {
                element.detachEvent('on' + name, observer);
            }
            catch ( e )
            {
            }
        }
    }
});

/* prevent memory leaks in IE */
if ( navigator.appVersion.match(/\bMSIE\b/) )
    Event.observe(window, 'unload', Event.unloadCache, false);
var Position = {
// set to true if needed, warning: firefox performance problems
// NOT neeeded for page scrolling, only if draggable contained in
// scrollable elements
    includeScrollOffsets: false,

// must be called before calling withinIncludingScrolloffset, every time the
// page is scrolled
    prepare: function()
    {
        this.deltaX = window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft || 0;
        this.deltaY = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
    },

    realOffset: function( element )
    {
        var valueT = 0, valueL = 0;
        do {
            valueT += element.scrollTop || 0;
            valueL += element.scrollLeft || 0;
            element = element.parentNode;
        }
        while ( element );
        return [valueL, valueT];
    },

    cumulativeOffset: function( element )
    {
        var valueT = 0, valueL = 0;
        do {
            valueT += element.offsetTop || 0;
            valueL += element.offsetLeft || 0;
            element = element.offsetParent;
        }
        while ( element );
        return [valueL, valueT];
    },

    positionedOffset: function( element )
    {
        var valueT = 0, valueL = 0;
        do {
            valueT += element.offsetTop || 0;
            valueL += element.offsetLeft || 0;
            element = element.offsetParent;
            if ( element )
            {
                p = Element.getStyle(element, 'position');
                if ( p == 'relative' || p == 'absolute' ) break;
            }
        }
        while ( element );
        return [valueL, valueT];
    },

    offsetParent: function( element )
    {
        if ( element.offsetParent ) return element.offsetParent;
        if ( element == document.body ) return element;

        while ( (element = element.parentNode) && element != document.body )
            if ( Element.getStyle(element, 'position') != 'static' )
                return element;

        return document.body;
    },

// caches x/y coordinate pair to use with overlap
    within: function( element, x, y )
    {
        if ( this.includeScrollOffsets )
            return this.withinIncludingScrolloffsets(element, x, y);
        this.xcomp = x;
        this.ycomp = y;
        this.offset = this.cumulativeOffset(element);

        return (y >= this.offset[1] && y < this.offset[1] + element.offsetHeight && x >= this.offset[0] &&
                x < this.offset[0] + element.offsetWidth);
    },

    withinIncludingScrolloffsets: function( element, x, y )
    {
        var offsetcache = this.realOffset(element);

        this.xcomp = x + offsetcache[0] - this.deltaX;
        this.ycomp = y + offsetcache[1] - this.deltaY;
        this.offset = this.cumulativeOffset(element);

        return (this.ycomp >= this.offset[1] && this.ycomp < this.offset[1] + element.offsetHeight &&
                this.xcomp >= this.offset[0] && this.xcomp < this.offset[0] + element.offsetWidth);
    },

// within must be called directly before
    overlap: function( mode, element )
    {
        if ( !mode ) return 0;
        if ( mode == 'vertical' )
            return ((this.offset[1] + element.offsetHeight) - this.ycomp) / element.offsetHeight;
        if ( mode == 'horizontal' )
            return ((this.offset[0] + element.offsetWidth) - this.xcomp) / element.offsetWidth;
    },

    page: function( forElement )
    {
        var valueT = 0, valueL = 0;

        var element = forElement;
        do {
            valueT += element.offsetTop || 0;
            valueL += element.offsetLeft || 0;

            // Safari fix
            if ( element.offsetParent == document.body )
                if ( Element.getStyle(element, 'position') == 'absolute' ) break;

        }
        while ( element = element.offsetParent );

        element = forElement;
        do {
            if ( !window.opera || element.tagName == 'BODY' )
            {
                valueT -= element.scrollTop || 0;
                valueL -= element.scrollLeft || 0;
            }
        }
        while ( element = element.parentNode );

        return [valueL, valueT];
    },

    clone: function( source, target )
    {
        var options = Object.extend({
            setLeft:    true,
            setTop:     true,
            setWidth:   true,
            setHeight:  true,
            offsetTop:  0,
            offsetLeft: 0
        }, arguments[2] || {})

        // find page position of source
        source = $(source);
        var p = Position.page(source);

        // find coordinate system to use
        target = $(target);
        var delta = [0, 0];
        var parent = null;
        // delta [0,0] will do fine with position: fixed elements,
        // position:absolute needs offsetParent deltas
        if ( Element.getStyle(target, 'position') == 'absolute' )
        {
            parent = Position.offsetParent(target);
            delta = Position.page(parent);
        }

        // correct by body offsets (fixes Safari)
        if ( parent == document.body )
        {
            delta[0] -= document.body.offsetLeft;
            delta[1] -= document.body.offsetTop;
        }

        // set position
        if ( options.setLeft )   target.style.left = (p[0] - delta[0] + options.offsetLeft) + 'px';
        if ( options.setTop )    target.style.top = (p[1] - delta[1] + options.offsetTop) + 'px';
        if ( options.setWidth )  target.style.width = source.offsetWidth + 'px';
        if ( options.setHeight ) target.style.height = source.offsetHeight + 'px';
    },

    absolutize: function( element )
    {
        element = $(element);
        if ( element.style.position == 'absolute' ) return;
        Position.prepare();

        var offsets = Position.positionedOffset(element);
        var top = offsets[1];
        var left = offsets[0];
        var width = element.clientWidth;
        var height = element.clientHeight;

        element._originalLeft = left - parseFloat(element.style.left || 0);
        element._originalTop = top - parseFloat(element.style.top || 0);
        element._originalWidth = element.style.width;
        element._originalHeight = element.style.height;

        element.style.position = 'absolute';
        element.style.top = top + 'px';
        ;
        element.style.left = left + 'px';
        ;
        element.style.width = width + 'px';
        ;
        element.style.height = height + 'px';
        ;
    },

    relativize: function( element )
    {
        element = $(element);
        if ( element.style.position == 'relative' ) return;
        Position.prepare();

        element.style.position = 'relative';
        var top = parseFloat(element.style.top || 0) - (element._originalTop || 0);
        var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

        element.style.top = top + 'px';
        element.style.left = left + 'px';
        element.style.height = element._originalHeight;
        element.style.width = element._originalWidth;
    }
}

// Safari returns margins on body which is incorrect if the child is absolutely
// positioned.  For performance reasons, redefine Position.cumulativeOffset for
// KHTML/WebKit only.
if ( /Konqueror|Safari|KHTML/.test(navigator.userAgent) )
{
    Position.cumulativeOffset = function( element )
    {
        var valueT = 0, valueL = 0;
        do {
            valueT += element.offsetTop || 0;
            valueL += element.offsetLeft || 0;
            if ( element.offsetParent == document.body )
                if ( Element.getStyle(element, 'position') == 'absolute' ) break;

            element = element.offsetParent;
        }
        while ( element );

        return [valueL, valueT];
    }
}

Element.addMethods();