function sack(file) {
 this.xmlhttp = null;

 this.resetData = function() {
 this.method = "POST";
 this.queryStringSeparator = "?";
 this.argumentSeparator = "&";
 this.URLString = "";
 this.encodeURIString = true;
 this.execute = false;
 this.element = null;
 this.elementObj = null;
 this.requestFile = file;
 this.vars = new Object();
 this.responseStatus = new Array(2);
 };

 this.resetFunctions = function() {
 this.onLoading = function() { };
 this.onLoaded = function() { };
 this.onInteractive = function() { };
 this.onCompletion = function() { };
 this.onError = function() { };
 this.onFail = function() { };
 };

 this.reset = function() {
 this.resetFunctions();
 this.resetData();
 };

 this.createAJAX = function() {
 try {
 this.xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
 } catch (e1) {
 try {
 this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
 } catch (e2) {
 this.xmlhttp = null;
 }
 }

 if (! this.xmlhttp) {
 if (typeof XMLHttpRequest != "undefined") {
 this.xmlhttp = new XMLHttpRequest();
 } else {
 this.failed = true;
 }
 }
 };

 this.setVar = function(name, value){
 this.vars[name] = Array(value, false);
 };

 this.encVar = function(name, value, returnvars) {
 if (true == returnvars) {
 return Array(encodeURIComponent(name), encodeURIComponent(value));
 } else {
 this.vars[encodeURIComponent(name)] = Array(encodeURIComponent(value), true);
 }
 }

 this.processURLString = function(string, encode) {
 encoded = encodeURIComponent(this.argumentSeparator);
 regexp = new RegExp(this.argumentSeparator + "|" + encoded);
 varArray = string.split(regexp);
 for (i = 0; i < varArray.length; i++){
 urlVars = varArray[i].split("=");
 if (true == encode){
 this.encVar(urlVars[0], urlVars[1]);
 } else {
 this.setVar(urlVars[0], urlVars[1]);
 }
 }
 }

 this.createURLString = function(urlstring) {
 if (this.encodeURIString && this.URLString.length) {
 this.processURLString(this.URLString, true);
 }

 if (urlstring) {
 if (this.URLString.length) {
 this.URLString += this.argumentSeparator + urlstring;
 } else {
 this.URLString = urlstring;
 }
 }

 // prevents caching of URLString
 this.setVar("rndval", new Date().getTime());

 urlstringtemp = new Array();
 for (key in this.vars) {
 if (false == this.vars[key][1] && true == this.encodeURIString) {
 encoded = this.encVar(key, this.vars[key][0], true);
 delete this.vars[key];
 this.vars[encoded[0]] = Array(encoded[1], true);
 key = encoded[0];
 }

 urlstringtemp[urlstringtemp.length] = key + "=" + this.vars[key][0];
 }
 if (urlstring){
 this.URLString += this.argumentSeparator + urlstringtemp.join(this.argumentSeparator);
 } else {
 this.URLString += urlstringtemp.join(this.argumentSeparator);
 }
 }

 this.runResponse = function() {
 eval(this.response);
 }

 this.runAJAX = function(urlstring) {
 if (this.failed) {
 this.onFail();
 } else {
 this.createURLString(urlstring);
 if (this.element) {
 this.elementObj = document.getElementById(this.element);
 }
 if (this.xmlhttp) {
 var self = this;
 if (this.method == "GET") {
 totalurlstring = this.requestFile + this.queryStringSeparator + this.URLString;
 this.xmlhttp.open(this.method, totalurlstring, true);
 } else {
 this.xmlhttp.open(this.method, this.requestFile, true);
 try {
 this.xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded")
 } catch (e) { }
 }

 this.xmlhttp.onreadystatechange = function() {
 switch (self.xmlhttp.readyState) {
 case 1:
 self.onLoading();
 break;
 case 2:
 self.onLoaded();
 break;
 case 3:
 self.onInteractive();
 break;
 case 4:
 self.response = self.xmlhttp.responseText;
 self.responseXML = self.xmlhttp.responseXML;
 self.responseStatus[0] = self.xmlhttp.status;
 self.responseStatus[1] = self.xmlhttp.statusText;

 if (self.execute) {
 self.runResponse();
 }

 if (self.elementObj) {
 elemNodeName = self.elementObj.nodeName;
 elemNodeName.toLowerCase();
 if (elemNodeName == "input"
 || elemNodeName == "select"
 || elemNodeName == "option"
 || elemNodeName == "textarea") {
 self.elementObj.value = self.response;
 } else {
 self.elementObj.innerHTML = self.response;
 }
 }
 if (self.responseStatus[0] == "200") {
 self.onCompletion();
 } else {
 self.onError();
 }

 self.URLString = "";
 break;
 }
 };

 this.xmlhttp.send(this.URLString);
 }
 }
 };

 this.reset();
 this.createAJAX();
}