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

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