var TargetID = "";
var FailureRedirect = "";

function InitializeAjax()
{
        var obj;
        var msxmlhttp = new Array(/*'Msxml2.XMLHTTP.5.0',*/'Msxml2.XMLHTTP.4.0','Msxml2.XMLHTTP.3.0','Msxml2.XMLHTTP','Microsoft.XMLHTTP');
        for (var i = 0; i < msxmlhttp.length; i++) {
                try {
                        obj = new ActiveXObject(msxmlhttp[i]);
                } catch (e) {
                        obj = null;
                }
        }

        if(!obj && typeof XMLHttpRequest != "undefined"){
                obj = new XMLHttpRequest();
        }

        return obj;
}

var Requests = new Array();

function CancelOperation()
{
        for (var i = 0; i < Requests.length; i++){
                Requests[i].abort();
        }
}

function PerformCall(func_name, args)
{
        var i, x, n;
        var uri;
        var post_data;
        var target_id;

        target_id = TargetID;
        if (typeof(RequestType) == "undefined" || RequestType == ""){
                RequestType = "GET";
        }

        uri = RemoteURI;

        if (RequestType == "GET"){
                if (uri.indexOf("?") == -1){
                        uri += "?MethodName=" + escape(func_name);
                } else {
                        uri += "&MethodName=" + escape(func_name);
                }

                uri += "&TargetID=" + escape(TargetID);
                uri += "&Rand=" + new Date().getTime();

                for (i = 0; i < args.length-1; i++){
                        uri += "&MethodArgs[]=" + escape(args[i]);
                }
                post_data = null;
        }
        else if (RequestType == "POST") {
                post_data = "MethodName=" + escape(func_name);
                post_data += "&TargetID=" + escape(TargetID);
                post_data += "&Rand=" + new Date().getTime();

                for (i = 0; i < args.length-1; i++){
                        post_data = post_data + "&MethodArgs[]=" + escape(args[i]);
                }
        }

        x = InitializeAjax();
        if (x == null) {
                if (FailureRedirect != "") {
                        location.href = FailureRedirect;
                        return false;
                } else {
                        return false;
                }
        } else {
                x.open(RequestType, uri, true);
                Requests[Requests.length] = x;

                if (RequestType == "POST") {
                        x.setRequestHeader("Method", "POST " + uri + " HTTP/1.1");
                        x.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
                }

                x.onreadystatechange = function() {
                        if (x.readyState != 4){
                                return;
                        }

                        var status;
                        var data;
                        var txt = x.responseText.replace(/^\s*|\s*$/g,"");
                        status = txt.charAt(0);
                        data = txt.substring(2);
                        if (status == "") {
                        } else if (status == "-")
                                alert("AJAX Error: " + data);
                        else {
                                if (target_id != "")
                                        document.getElementById(target_id).innerHTML = eval(data);
                                else {
                                        try {
                                                var callback;
                                                var extra_data = false;
                                                if (typeof args[args.length-1] == "object") {
                                                        callback = args[args.length-1].callback;
                                                        extra_data = args[args.length-1].extra_data;
                                                } else {
                                                        callback = args[args.length-1];
                                                }
                                                callback(eval(data), extra_data);
                                        } catch (e) {
                                                alert("ERROR: " + e + ": Could not eval " + data );
                                        }
                                }
                        }
                }
        }

        x.send(post_data);
        delete x;
        return true;
}