var XMLHttpArray = [
        function() {return new XMLHttpRequest()},
        function() {return new ActiveXObject("Msxml2.XMLHTTP")},
        function() {return new ActiveXObject("Msxml2.XMLHTTP")},
        function() {return new ActiveXObject("Microsoft.XMLHTTP")}
	];
function createXMLHTTPObject()
{
        var xmlhttp = false;
        for(var i=0; i<XMLHttpArray.length; i++){
                try{
                        xmlhttp = XMLHttpArray[i]();
                }catch(e){
                        continue;
                }
                break;
        }
        return xmlhttp;
}
function AjaxRequest(url, callback)
{
	var req = createXMLHTTPObject();
	req.onreadystatechange= function(){
			if(req.readyState != 4) return;
			if(req.status != 200) return;
			callback(req);
		}
	req.open("GET",url,true);
	req.send(null);
}