function getXmlHttp(){
	var msxmls = ["MSXML3", "MSXML2", "Microsoft"];
	for (var i=0; i < msxmls.length; i++) {
		try {
			return new ActiveXObject(msxmls[i]+".XMLHTTP");
		} catch (e) { }
	}
	return new XMLHttpRequest();
}

var xmlhttp = getXmlHttp();