function DWREngine() {
}


DWREngine.setErrorHandler = function(handler) {
    DWREngine._errorHandler = handler;
};


DWREngine.setWarningHandler = function(handler) {
    DWREngine._warningHandler = handler;
};


DWREngine.setTimeout = function(timeout) {
    DWREngine._timeout = timeout;
};


DWREngine.setPreHook = function(handler) {
    DWREngine._preHook = handler;
};


DWREngine.setPostHook = function(handler) {
    DWREngine._postHook = handler;
};


DWREngine.XMLHttpRequest = 1;


DWREngine.IFrame = 2;


DWREngine.setMethod = function(newmethod) {
    if (newmethod != DWREngine.XMLHttpRequest && newmethod != DWREngine.IFrame) {
        DWREngine._handleError("Remoting method must be one of DWREngine.XMLHttpRequest or DWREngine.IFrame");
        return;
    }
    DWREngine._method = newmethod;
};


DWREngine.setVerb = function(verb) {
    if (verb != "GET" && verb != "POST") {
        DWREngine._handleError("Remoting verb must be one of GET or POST");
        return;
    }
    DWREngine._verb = verb;
};


DWREngine.setOrdered = function(ordered) {
    DWREngine._ordered = ordered;
};


DWREngine.setAsync = function(async) {
    DWREngine._async = async;
};


DWREngine.defaultMessageHandler = function(message) {
    if (typeof message == "object" && message.name == "Error" && message.description) {
        alert("Error: " + message.description);
    }
    else {
        alert(message);
    }
};


DWREngine.beginBatch = function() {
    if (DWREngine._batch) {
        DWREngine._handleError("Batch already started.");
        return;
    }

    DWREngine._batch = {};
    DWREngine._batch.map = {};
    DWREngine._batch.paramCount = 0;
    DWREngine._batch.map.callCount = 0;
    DWREngine._batch.ids = [];
    DWREngine._batch.preHooks = [];
    DWREngine._batch.postHooks = [];
};


DWREngine.endBatch = function(options) {
    var batch = DWREngine._batch;
    if (batch == null) {
        DWREngine._handleError("No batch in progress.");
        return;
    }

    if (options && options.preHook) batch.preHooks.unshift(options.preHook);
    if (options && options.postHook) batch.postHooks.push(options.postHook);
    if (DWREngine._preHook) batch.preHooks.unshift(DWREngine._preHook);
    if (DWREngine._postHook) batch.postHooks.push(DWREngine._postHook);

    if (batch.method == null) batch.method = DWREngine._method;
    if (batch.verb == null) batch.verb = DWREngine._verb;
    if (batch.async == null) batch.async = DWREngine._async;
    if (batch.timeout == null) batch.timeout = DWREngine._timeout;

    batch.completed = false;


    DWREngine._batch = null;


    if (!DWREngine._ordered) {
        DWREngine._sendData(batch);
        DWREngine._batches[DWREngine._batches.length] = batch;
    }
    else {
        if (DWREngine._batches.length == 0) {

            DWREngine._sendData(batch);
            DWREngine._batches[DWREngine._batches.length] = batch;
        }
        else {

            DWREngine._batchQueue[DWREngine._batchQueue.length] = batch;
        }
    }
};


DWREngine._errorHandler = DWREngine.defaultMessageHandler;


DWREngine._warningHandler = DWREngine.defaultMessageHandler;


DWREngine._preHook = null;


DWREngine._postHook = null;


DWREngine._batches = [];


DWREngine._batchQueue = [];


DWREngine._handlersMap = {};


DWREngine._method = DWREngine.XMLHttpRequest;


DWREngine._verb = "GET";


DWREngine._ordered = false;


DWREngine._async = true;


DWREngine._batch = null;


DWREngine._timeout = 0;


DWREngine._DOMDocument = ["Msxml2.DOMDocument.5.0", "Msxml2.DOMDocument.4.0", "Msxml2.DOMDocument.3.0", "MSXML2.DOMDocument", "MSXML.DOMDocument", "Microsoft.XMLDOM"];


DWREngine._XMLHTTP = ["Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP", "Microsoft.XMLHTTP"];


DWREngine._execute = function(path, scriptName, methodName, vararg_params) {
    var singleShot = false;

    if (DWREngine._batch == null) {
        DWREngine.beginBatch();
        singleShot = true;
    }

    var args = [];
    for (var i = 0; i < arguments.length - 3; i++) {
        args[i] = arguments[i + 3];
    }

    if (DWREngine._batch.path == null) {
        DWREngine._batch.path = path;
    }
    else {
        if (DWREngine._batch.path != path) {
            DWREngine._handleError("Can't batch requests to multiple DWR Servlets.");
            return;
        }
    }


    var params;
    var callData;
    var firstArg = args[0];
    var lastArg = args[args.length - 1];

    if (typeof firstArg == "function") {
        callData = { callback:args.shift() };
        params = args;
    }
    else if (typeof lastArg == "function") {
        callData = { callback:args.pop() };
        params = args;
    }
    else if (typeof lastArg == "object" && lastArg.callback != null && typeof lastArg.callback == "function") {
        callData = args.pop();
        params = args;
    }
    else if (firstArg == null) {


        if (lastArg == null && args.length > 2) {
            if (DWREngine._warningHandler) {
                DWREngine._warningHandler("Ambiguous nulls at start and end of parameter list. Which is the callback function?");
            }
        }
        callData = { callback:args.shift() };
        params = args;
    }
    else if (lastArg == null) {
        callData = { callback:args.pop() };
        params = args;
    }
    else {
        if (DWREngine._warningHandler) {
            DWREngine._warningHandler("Missing callback function or metadata object.");
        }
        return;
    }


    var random = Math.floor(Math.random() * 10001);
    var id = (random + "_" + new Date().getTime()).toString();
    var prefix = "c" + DWREngine._batch.map.callCount + "-";
    DWREngine._batch.ids.push(id);


    if (callData.method != null) {
        DWREngine._batch.method = callData.method;
        delete callData.method;
    }
    if (callData.verb != null) {
        DWREngine._batch.verb = callData.verb;
        delete callData.verb;
    }
    if (callData.async != null) {
        DWREngine._batch.async = callData.async;
        delete callData.async;
    }
    if (callData.timeout != null) {
        DWREngine._batch.timeout = callData.timeout;
        delete callData.timeout;
    }


    if (callData.preHook != null) {
        DWREngine._batch.preHooks.unshift(callData.preHook);
        delete callData.preHook;
    }
    if (callData.postHook != null) {
        DWREngine._batch.postHooks.push(callData.postHook);
        delete callData.postHook;
    }


    if (callData.errorHandler == null) callData.errorHandler = DWREngine._errorHandler;
    if (callData.warningHandler == null) callData.warningHandler = DWREngine._warningHandler;


    DWREngine._handlersMap[id] = callData;

    DWREngine._batch.map[prefix + "scriptName"] = scriptName;
    DWREngine._batch.map[prefix + "methodName"] = methodName;
    DWREngine._batch.map[prefix + "id"] = id;


    DWREngine._addSerializeFunctions();
    for (i = 0; i < params.length; i++) {
        DWREngine._serializeAll(DWREngine._batch, [], params[i], prefix + "param" + i);
    }
    DWREngine._removeSerializeFunctions();


    DWREngine._batch.map.callCount++;
    if (singleShot) {
        DWREngine.endBatch();
    }
};


function DWR_AbortRequest() {
    clearInterval(DWREngine.thisBatch.interval);
    DWREngine._abortRequest(DWREngine.thisBatch);
}

DWREngine._sendData = function(batch) {
    DWREngine.batchCopy = batch;	
    if (batch.map.callCount == 0) return;

    for (var i = 0; i < batch.preHooks.length; i++) {
        batch.preHooks[i]();
    }
    batch.preHooks = null;

    if (batch.timeout && batch.timeout != 0) {
        if (DWREngine.thisBatch && DWREngine.thisBatch.interval) {
            clearInterval(DWREngine.thisBatch.interval);
        }
        DWREngine.thisBatch.interval = setInterval("DWR_AbortRequest()", batch.timeout);
    }

    var statsInfo;
    if (batch.map.callCount == 1) {
        statsInfo = batch.map["c0-scriptName"] + "." + batch.map["c0-methodName"] + ".dwr";
    }
    else {
        statsInfo = "Multiple." + batch.map.callCount + ".dwr";
    }

    if (batch.method == DWREngine.XMLHttpRequest) {
        if (window.XMLHttpRequest && navigator.userAgent.indexOf("MSIE 7") == -1) {
            batch.req = new XMLHttpRequest();
        }

        else if (window.ActiveXObject && !(navigator.userAgent.indexOf('Mac') >= 0 && navigator.userAgent.indexOf("MSIE") >= 0)) {
            batch.req = DWREngine._newActiveXObject(DWREngine._XMLHTTP);
        }
    }

    var query = "";
    var prop;
    if (batch.req) {
        batch.map.xml = "true";

        if (batch.async) {
            batch.req.onreadystatechange = function() {
                DWREngine._stateChange(batch);
            };
        }

        var indexSafari = navigator.userAgent.indexOf('Safari/');
        if (indexSafari >= 0) {

            var version = navigator.userAgent.substring(indexSafari + 7);
            var verNum = parseInt(version, 10);
            if (verNum < 400) {
                batch.verb == "GET";
            }


        }
        if (batch.verb == "GET") {


            batch.map.callCount = "" + batch.map.callCount;

            for (prop in batch.map) {
                var qkey = encodeURIComponent(prop);
                var qval = encodeURIComponent(batch.map[prop]);
                if (qval == "") {
                    if (DWREngine._warningHandler) {
                        DWREngine._warningHandler("Found empty qval for qkey=" + qkey);
                    }
                }
                query += qkey + "=" + qval + "&";
            }
            query = query.substring(0, query.length - 1);

            try {
                batch.req.open("GET", batch.path + "/exec/" + statsInfo + "?" + query, batch.async);
                batch.req.send(null);
                if (!batch.async) {
                    DWREngine._stateChange(batch);
                }
            }
            catch (ex) {
                DWREngine._handleMetaDataError(null, ex);
            }
        }
        else {
            for (prop in batch.map) {
                if (typeof batch.map[prop] != "function") {
                    query += prop + "=" + batch.map[prop] + "\n";
                }
            }

            try {


                batch.req.open("POST", batch.path + "/exec/" + statsInfo, batch.async);
                batch.req.setRequestHeader('Content-Type', 'text/plain');
                batch.req.send(query);
                if (!batch.async) {
                    DWREngine._stateChange(batch);
                }
            }
            catch (ex) {
                DWREngine._handleMetaDataError(null, ex);
            }
        }
    } else {
        DWREngine._method = 2;
        batch.map.xml = "false";

        if (DWREngine._iframe == null) {
            var iframe = document.createElement('iframe');
            iframe.id = "RSIFrame";
            iframe.setAttribute('style', 'position: absolute; top: -5px; width:1px; height:1px; border:0px;');

            document.body.appendChild(iframe);

            DWREngine._iframe = new Object();
            DWREngine._iframe.document = new Object();
            DWREngine._iframe.document.location = new Object();
            DWREngine._iframe.document.location.iframe = document.getElementById('RSIFrame');
            DWREngine._iframe.document.location.replace = function(location) {
                this.iframe.src = location;
            }
        }

        if (batch.verb == "GET") {
            for (prop in batch.map) {
                if (typeof batch.map[prop] != "function") {
                    query += encodeURIComponent(prop) + "=" + encodeURIComponent(batch.map[prop]) + "&";
                }
            }
            query = query.substring(0, query.length - 1);
            var url = batch.path + "/exec/" + statsInfo + "?" + query;

            var IFrameDoc = DWREngine._iframe.document;
            IFrameDoc.location.replace(url);
        }
    }
};

window.onbeforeunload = function() {
	if (DWREngine.batchCopy) {
	        DWREngine.batchCopy.completed=true;
        	if (DWREngine.batchCopy.req) {
        		DWREngine.batchCopy.req.abort();
        	}	
        }
}

DWREngine._stateChange = function(batch) {
	
    if (!batch.completed && batch.req.readyState == 4) {
        try {
            var reply = batch.req.responseText;
            var status = batch.req.status;
            
            if (reply == null || reply == "") {
                DWREngine._handleMetaDataError(null, "No data received from server");
                return;
            }


            if (reply.search("DWREngine._handle") == -1) {
                DWREngine._handleMetaDataError(null, "Invalid reply from server");
                return;
            }

            if (status != 200) {
                if (reply == null) reply = "Unknown error occured";
                DWREngine._handleMetaDataError(null, reply);
                return;
            }
			DWREngine.batchCopy = null;
            eval(reply);


            DWREngine._clearUp(batch);
        }
        catch (ex) {
            if (ex == null) ex = "Unknown error occured";
            DWREngine._handleMetaDataError(null, ex);
        }
        finally {


            if (DWREngine._batchQueue.length != 0) {
                var sendbatch = DWREngine._batchQueue.shift();
                DWREngine._sendData(sendbatch);
                DWREngine._batches[DWREngine._batches.length] = sendbatch;
            }
        }
    }
};


DWREngine._handleResponse = function(id, reply) {
    //NEUFUtils.debug(new Date().getTime()- VODApp.startDate.getTime())
    var handlers = DWREngine._handlersMap[id];
    DWREngine._handlersMap[id] = null;

    if (handlers) {


        try {
            if (handlers.callback) handlers.callback(reply);
        }
        catch (ex) {
            DWREngine._handleMetaDataError(handlers, ex);
        }
    }


    if (DWREngine._method == DWREngine.IFrame) {
        var responseBatch = DWREngine._batches[DWREngine._batches.length - 1];

        if (responseBatch.map["c" + (responseBatch.map.callCount - 1) + "-id"] == id) {
            DWREngine._clearUp(responseBatch);
        }
    }
};


DWREngine._handleServerError = function(id, error) {

    var handlers = DWREngine._handlersMap[id];
    DWREngine._handlersMap[id] = null;
    if (error.message) {
        DWREngine._handleMetaDataError(handlers, error.message, error);
    }
    else {
        DWREngine._handleMetaDataError(handlers, error);
    }
};


DWREngine._abortRequest = function(batch) {
    if (batch && !batch.completed) {
        DWREngine._clearUp(batch);
        if (batch.req) batch.req.abort();

        var handlers;
        var id;
        for (var i = 0; i < batch.ids.length; i++) {
            id = batch.ids[i];
            handlers = DWREngine._handlersMap[id];
            DWREngine._handleMetaDataError(handlers, "Timeout");
        }
    }
};


DWREngine._clearUp = function(batch) {
    if (batch.completed) {
        alert("double complete");
        return;
    }
                  
    if (DWREngine.thisBatch) {
        clearInterval(DWREngine.thisBatch.interval);
    }

    if (batch.req) {
        delete batch.req;
        batch.req = null;
    }

    for (var i = 0; i < batch.postHooks.length; i++) {
        batch.postHooks[i]();
    }
    batch.postHooks = null;


    for (var i = 0; i < DWREngine._batches.length; i++) {
        if (DWREngine._batches[i] == batch) {
            DWREngine._batches.splice(i, 1);
            break;
        }
    }

    batch.completed = true;
};


DWREngine._handleError = function(reason, ex) {
    if (DWREngine._errorHandler) {
        DWREngine._errorHandler(reason, ex);
    }
};


DWREngine._handleMetaDataError = function(handlers, reason, ex) {
    if (handlers && typeof handlers.errorHandler == "function") {
        handlers.errorHandler(reason, ex);
    }
    else {
        DWREngine._handleError(reason, ex);
    }
};


DWREngine._addSerializeFunctions = function() {
    Object.prototype.dwrSerialize = DWREngine._serializeObject;
    Array.prototype.dwrSerialize = DWREngine._serializeArray;
    Boolean.prototype.dwrSerialize = DWREngine._serializeBoolean;
    Number.prototype.dwrSerialize = DWREngine._serializeNumber;
    String.prototype.dwrSerialize = DWREngine._serializeString;
    Date.prototype.dwrSerialize = DWREngine._serializeDate;
};


DWREngine._removeSerializeFunctions = function() {
    delete Object.prototype.dwrSerialize;
    delete Array.prototype.dwrSerialize;
    delete Boolean.prototype.dwrSerialize;
    delete Number.prototype.dwrSerialize;
    delete String.prototype.dwrSerialize;
    delete Date.prototype.dwrSerialize;
};


DWREngine._serializeAll = function(batch, referto, data, name) {
    if (data == null) {
        batch.map[name] = "null:null";
        return;
    }

    switch (typeof data) {
        case "boolean":
            batch.map[name] = "boolean:" + data;
            break;

        case "number":
            batch.map[name] = "number:" + data;
            break;

        case "string":
            batch.map[name] = "string:" + encodeURIComponent(data);
            break;

        case "object":
            if (data.dwrSerialize) {
                batch.map[name] = data.dwrSerialize(batch, referto, data, name);
            }
            else if (data.nodeName) {
                batch.map[name] = DWREngine._serializeXml(batch, referto, data, name);
            }
            else {
                if (DWREngine._warningHandler) {
                    DWREngine._warningHandler("Object without dwrSerialize: " + typeof data + ", attempting default converter.");
                }
                batch.map[name] = "default:" + data;
            }
            break;

        case "function":

            break;

        default:
            if (DWREngine._warningHandler) {
                DWREngine._warningHandler("Unexpected type: " + typeof data + ", attempting default converter.");
            }
            batch.map[name] = "default:" + data;
            break;
    }
};


DWREngine._lookup = function(referto, data, name) {
    var lookup;

    for (var i = 0; i < referto.length; i++) {
        if (referto[i].data == data) {
            lookup = referto[i];
            break;
        }
    }
    if (lookup) {
        return "reference:" + lookup.name;
    }
    referto.push({ data:data, name:name });
    return null;
};


DWREngine._serializeObject = function(batch, referto, data, name) {
    var ref = DWREngine._lookup(referto, this, name);
    if (ref) return ref;

    if (data.nodeName) {
        return DWREngine._serializeXml(batch, referto, data, name);
    }


    var reply = "Object:{";
    var element;
    for (element in this) {
        if (element != "dwrSerialize") {
            batch.paramCount++;
            var childName = "c" + DWREngine._batch.map.callCount + "-e" + batch.paramCount;
            DWREngine._serializeAll(batch, referto, this[element], childName);

            reply += encodeURIComponent(element);
            reply += ":reference:";
            reply += childName;
            reply += ", ";
        }
    }

    if (reply.substring(reply.length - 2) == ", ") {
        reply = reply.substring(0, reply.length - 2);
    }
    reply += "}";

    return reply;
};


DWREngine._serializeXml = function(batch, referto, data, name) {
    var ref = DWREngine._lookup(referto, this, name);
    if (ref) {
        return ref;
    }
    var output;
    if (window.XMLSerializer) {
        var serializer = new XMLSerializer();
        output = serializer.serializeToString(data);
    }
    else {
        output = data.toXml;
    }
    return "XML:" + encodeURIComponent(output);
};


DWREngine._serializeArray = function(batch, referto, data, name) {
    var ref = DWREngine._lookup(referto, this, name);
    if (ref) return ref;

    var reply = "Array:[";
    for (var i = 0; i < this.length; i++) {
        if (i != 0) {
            reply += ",";
        }

        batch.paramCount++;
        var childName = "c" + DWREngine._batch.map.callCount + "-e" + batch.paramCount;
        DWREngine._serializeAll(batch, referto, this[i], childName);
        reply += "reference:";
        reply += childName;
    }
    reply += "]";

    return reply;
};


DWREngine._serializeBoolean = function(batch, referto, data, name) {
    return "Boolean:" + this;
};


DWREngine._serializeNumber = function(batch, referto, data, name) {
    return "Number:" + this;
};


DWREngine._serializeString = function(batch, referto, data, name) {
    return "String:" + encodeURIComponent(this);
};


DWREngine._serializeDate = function(batch, referto, data, name) {
    return "Date:" + this.getTime();
};


DWREngine._unserializeDocument = function(xml) {
    var dom;
    if (window.DOMParser) {
        var parser = new DOMParser();
        dom = parser.parseFromString(xml, "text/xml");
        if (!dom.documentElement || dom.documentElement.tagName == "parsererror") {
            var message = dom.documentElement.firstChild.data;
            message += "\n" + dom.documentElement.firstChild.nextSibling.firstChild.data;
            throw message;
        }
        return dom;
    }
    else if (window.ActiveXObject) {
        dom = DWREngine._newActiveXObject(DWREngine._DOMDocument);
        dom.loadXML(xml);

        return dom;
    }


    else {
        var div = document.createElement('div');
        div.innerHTML = xml;
        return div;
    }
};


DWREngine._newActiveXObject = function(axarray) {
    var returnValue;
    for (var i = 0; i < axarray.length; i++) {
        try {
            returnValue = new ActiveXObject(axarray[i]);
            break;
        }
        catch (ex) {
        }
    }
    return returnValue;
};


if (typeof window.encodeURIComponent === 'undefined') {
    DWREngine._utf8 = function(wide) {
        wide = "" + wide;
        var c;
        var s;
        var enc = "";
        var i = 0;
        while (i < wide.length) {
            c = wide.charCodeAt(i++);

            if (c >= 0xDC00 && c < 0xE000) continue;
            if (c >= 0xD800 && c < 0xDC00) {
                if (i >= wide.length) continue;
                s = wide.charCodeAt(i++);
                if (s < 0xDC00 || c >= 0xDE00) continue;
                c = ((c - 0xD800) << 10) + (s - 0xDC00) + 0x10000;
            }

            if (c < 0x80) {
                enc += String.fromCharCode(c);
            }
            else if (c < 0x800) {
                enc += String.fromCharCode(0xC0 + (c >> 6), 0x80 + (c & 0x3F));
            }
            else if (c < 0x10000) {
                enc += String.fromCharCode(0xE0 + (c >> 12), 0x80 + (c >> 6 & 0x3F), 0x80 + (c & 0x3F));
            }
            else {
                enc += String.fromCharCode(0xF0 + (c >> 18), 0x80 + (c >> 12 & 0x3F), 0x80 + (c >> 6 & 0x3F), 0x80 + (c & 0x3F));
            }
        }
        return enc;
    }

    DWREngine._hexchars = "0123456789ABCDEF";

    DWREngine._toHex = function(n) {
        return DWREngine._hexchars.charAt(n >> 4) + DWREngine._hexchars.charAt(n & 0xF);
    }

    DWREngine._okURIchars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-";

    window.encodeURIComponent = function(s) {
        s = DWREngine._utf8(s);
        var c;
        var enc = "";
        for (var i = 0; i < s.length; i++) {
            if (DWREngine._okURIchars.indexOf(s.charAt(i)) == -1) {
                enc += "%" + DWREngine._toHex(s.charCodeAt(i));
            }
            else {
                enc += s.charAt(i);
            }
        }
        return enc;
    }
}


if (typeof Array.prototype.splice === 'undefined') {
    Array.prototype.splice = function(ind, cnt)
    {
        if (arguments.length == 0) {
            return ind;
        }
        if (typeof ind != "number") {
            ind = 0;
        }
        if (ind < 0) {
            ind = Math.max(0, this.length + ind);
        }
        if (ind > this.length) {
            if (arguments.length > 2) {
                ind = this.length;
            }
            else {
                return [];
            }
        }
        if (arguments.length < 2) {
            cnt = this.length - ind;
        }

        cnt = (typeof cnt == "number") ? Math.max(0, cnt) : 0;
        removeArray = this.slice(ind, ind + cnt);
        endArray = this.slice(ind + cnt);
        this.length = ind;

        for (var i = 2; i < arguments.length; i++) {
            this[this.length] = arguments[i];
        }
        for (i = 0; i < endArray.length; i++) {
            this[this.length] = endArray[i];
        }

        return removeArray;
    }
}


if (typeof Array.prototype.shift === 'undefined') {
    Array.prototype.shift = function(str) {
        var val = this[0];
        for (var i = 1; i < this.length; ++i) {
            this[i - 1] = this[i];
        }
        this.length--;
        return val;
    }
}


if (typeof Array.prototype.unshift === 'undefined') {
    Array.prototype.unshift = function() {
        var i = unshift.arguments.length;
        for (var j = this.length - 1; j >= 0; --j) {
            this[j + i] = this[j];
        }
        for (j = 0; j < i; ++j) {
            this[j] = unshift.arguments[j];
        }
    }
}


if (typeof Array.prototype.push === 'undefined') {
    Array.prototype.push = function() {
        var sub = this.length;
        for (var i = 0; i < push.arguments.length; ++i) {
            this[sub] = push.arguments[i];
            sub++;
        }
    }
}


if (typeof Array.prototype.pop === 'undefined') {
    Array.prototype.pop = function() {
        var lastElement = this[this.length - 1];
        this.length--;
        return lastElement;
    }
}