function myAjax(url, mtd, retType, options) 
{ 
	this.url = url;
	this.method = mtd.toUpperCase() || 'GET';

	this.returnType = retType.toUpperCase() || 'XML';
	
	this.options = options || {};
	this.params = this.options.params || '' ;
	this.params += "&dummy=" + new Date().getTime();
	this.callBack = this.options.callBack || '';
	this.onError = this.options.onError || 'alert';
	this.onTimeOut = this.options.onTimeOut || '';
	this.header = this.options.header || new Array();
//	this.userId = this.options.userid || null;
//	this.password = this.options.password || null;
	this.httpObj = null;
	this.timeout = false;
	this.timeoutStart = new Date().getTime();
	this.timeoutConstant = this.options.timeOut || 150 * 1000;  // time in miliseconds
	this.config();
	this.createAjax();
};

myAjax.prototype.config = function (){
	this.httpObj = this.httpRequest();
	if (this.url.length == 0 ){
		alert('please send HTTP url for ajax request...')
		return false;
	}
	if (this.returnType != 'XML' && this.returnType != 'TEXT'){
		this.returnType = 'XML';
	}
};

myAjax.prototype.httpRequest = function (){
	var httprequest = null;
	if (window.XMLHttpRequest){ // if Mozilla, Safari etc
		httprequest = new XMLHttpRequest();
	}else if (window.ActiveXObject){ // if IE
		try {
			httprequest = new ActiveXObject("Msxml2.XMLHTTP");
		}catch (e){
			try{
				httprequest = new ActiveXObject("Microsoft.XMLHTTP");
			}catch (e){
				Alert('Your browser does not support HTTP request...');
				return false;
			}
		}
	}
	if (httprequest.overrideMimeType)
		httprequest.overrideMimeType('text/xml')

	return httprequest
};


myAjax.prototype.checkTimeout = function (){
	var curTime = new Date().getTime();
	if (( curTime - this.timeoutStart) > this.timeoutConstant){
		 this.timeout = true;
	}
	if (this.timeout){
		if (this.onTimeOut && this.onTimeOut.length > 0 ){
			this.hideProgress();
			eval(this.onTimeOut+'(this.httpObj)')
		}else {
			this.hideProgress();
			alert('Ajax call time out on status:\n'+this.httpObj.readyState)
		}
		return true;
	}
	return false;
};


myAjax.prototype.createAjax = function (){
	var owner = this; 
	this.httpObj.onreadystatechange = function(){
		//owner.showProgress();
		if (owner.checkTimeout()) {
			owner.httpObj.abort();
			owner.httpObj = null;
			return false;
		}
		if (owner.httpObj && owner.httpObj.readyState == 4) { // done
			var ajaxResponse = null;
			//owner.hideProgress();
			switch (owner.httpObj.status) {
				case 200:
					if (owner.httpObj.responseText.indexOf('ErrorOnSessionExpire') > -1 ) {
						if (owner.onError || owner.onError.length > 0){
							eval(owner.onError+ '(owner.httpObj)')
						}else{
							owner.handleErrFullPage('Error: (ErrorOnSessionExpire) \n\nURL: '+owner.url+"\n\nMessage: "+owner.httpObj.responseText,owner.httpObj);
							break;
						}
					}
					else {
						if (owner.returnType == 'XML') { 
							ajaxResponse = owner.httpObj.responseXML;
						}else{
							ajaxResponse = owner.httpObj.responseText;
						}

						if (owner.callBack || owner.callBack > 0){
							eval(owner.callBack + '(ajaxResponse)');
						}
					}
					break;
				case 404:
					alert('Error: Not Found. The requested URL:\n ' + owner.url + '\n\nCould not be found.\n'+owner.httpObj.statusText);
					break;
				default:
					owner.handleErrFullPage('Error: (Other)\n\nURL: '+owner.url+"\n\nMessage: "+owner.httpObj.responseText,owner.httpObj);
					break;
			}
		}
	}
	// Added for firfox
	try {
		if (!document.all && netscape.security.PrivilegeManager.enablePrivilege) {
			netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
		}
	} catch (e) {
		//alert("(Mozilla) - " + e);
	}
	// end
	if (this.httpObj && this.method == 'POST'){
		this.httpObj.open(this.method, this.url, true); 
		if (this.httpObj){
			// set default request header 
			this.httpObj.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8"); 
			this.httpObj.setRequestHeader("Content-length", this.params.length);
			this.httpObj.setRequestHeader("Connection", "close");
			for (var x=0; x < this.header.length ;x++ )	{
				if (this.header[x][0].toUpperCase() != "Content-Type".toUpperCase() && this.header[x][0].toUpperCase() != "Content-length".toUpperCase() && this.header[x][0].toUpperCase() != "Connection".toUpperCase() )
				{
					this.httpObj.setRequestHeader(this.header[x][0],this.header[x][1])
				}
				
			}
			this.httpObj.send(this.params);
		}
	}
	if (this.httpObj && this.method == 'GET'){
		this.url = this.url + (this.params.length > 0 ? '?'+this.params : '')
		this.httpObj.open(this.method, this.url, true); 
		if (this.httpObj){
			this.httpObj.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
			this.httpObj.send(null);
		}
	}
};


myAjax.prototype.showProgress = function(){
	var processAjax = document.getElementById('processAjax');
	if (!processAjax)
	{
		processAjax = document.createElement('div');
		processAjax.id = 'processAjax'
		processAjax.className = 'processAjax'
		processAjax.style.cssText = "position:absolute;left:0px;top:0px;width:100px;height:100px;background-color:#aaaaaa;z-index:99;filter:alpha(opacity=40);text-align:center;vertical-align:center;"
		span = document.createElement('span');
		span.innerHTML = '&nbsp;'
		//span.style.cssText = 'width:100%;height:100%;background:url(../images/myloader.gif) center center no-repeat;'
		processAjax.appendChild(span);
		document.body.appendChild(processAjax);
	}
	processAjax.style.display='block';
	var ajaxPos = this.windowCenter({'width':processAjax.offsetWidth,'height':processAjax.offsetHeight})
	processAjax.style.left = ajaxPos.x
	processAjax.style.top = ajaxPos.y
};

myAjax.prototype.hideProgress = function(){
	var ajaxProcess = document.getElementById('processAjax');
	if (ajaxProcess){
		ajaxProcess.style.display='none'
	}
};

myAjax.prototype.getUrl = function(){
	return this.url;
};

myAjax.prototype.getResponse = function(){
	if (this.httpObj.readyState == 4 && this.httpObj.status == 200) {
		if (this.returnType.toUpperCase() == 'XML') { 
			return this.httpObj.responseXML;
		}else{
			return this.httpObj.responseText;
		} 
	}
	return null;
};



myAjax.prototype.handleErrFullPage = function(strIn,obj) {
	var errorWin;
	try {
		alert(strIn+'\n\nStatus: '+obj.status);
		
	}
	catch(e) {
		alert('An error occurred, but the error message cannot be displayed because of your browser\'s pop-up blocker.\n' +
		'Please allow pop-ups from this Web site.');
	}
	this.httpObj = null
	return false;
};



myAjax.prototype.getPageScroll =function () {
	if(!window.pageYOffset)	{
		//strict mode
		if(!(document.documentElement.scrollTop == 0))	{
			offsetY = document.documentElement.scrollTop;
			offsetX = document.documentElement.scrollLeft;
		}
		//quirks mode
		else{
			offsetY = document.body.scrollTop;
			offsetX = document.body.scrollLeft;
		}
	}
	//w3c
	else{
		offsetX = window.pageXOffset;
		offsetY = window.pageYOffset;
	}
  return { 'x': offsetX, 'y': offsetY };
};



//-----------------------------------------------------------------------------
myAjax.prototype.windowCenter= function ()	{
	var hWnd = (arguments[0] != null) ? arguments[0] : {width:0,height:0};
	var _x = 0;
	var _y = 0;
	_pgScroll = this.getPageScroll();
	_winSize = this.getWindowSize();
	_x = ((_winSize.width - hWnd.width)/2)+_pgScroll.x;
	_y = ((_winSize.height - hWnd.height)/2)+_pgScroll.y;

	return{x:_x,y:_y};
};
//-----------------------------------------------------------------------------
myAjax.prototype.getWindowSize= function (){
	var w = 0;
	var h = 0;
	//IE
	if(!window.innerWidth){
		//strict mode
		if(!(document.documentElement.clientWidth == 0)){
			w = document.documentElement.clientWidth;
			h = document.documentElement.clientHeight;
		}
		//quirks mode
		else{
			w = document.body.clientWidth;
			h = document.body.clientHeight;
		}
	}
	//w3c
	else{
		w = window.innerWidth;
		h = window.innerHeight;
	}
	return {width:w,height:h};
};