function getXMLHttp(){
	var XMLHttp = null;
	if (window.XMLHttpRequest){
		try {
			XMLHttp = new XMLHttpRequest();
		} catch (e) {}
	}else if (window.ActiveXObject){
		try{
			XMLHttp = new ActiveXObject("Msxml2.XMLHTTP")
		} catch (e){
			try {
				XMLHttp = new ActiveXObject(
					"Microsoft.XMLHTTP")
			} catch (e) {}
		}
	}
	return XMLHttp;
}