var XMLHTTPFactories = [
	function(){ return new XMLHttpRequest() },
	function(){ return new ActiveXObject('Msxml2.XMLHTTP') },
	function(){ return new ActiveXObject('Msxml3.XMLHTTP') },
	function(){ return new ActiveXObject('Microsoft.XMLHTTP') }
];

function getXmlHttp(){
	var oXmlHttp = false;
	for(var i=0 ; i<XMLHTTPFactories.length ; i++){
		try {
			oXmlHttp = XMLHTTPFactories[i]();
		}catch(e){ continue; }
		break;
	}
	return oXmlHttp;
}