function xmlhttp(){
	var xmlhttp;
	try{xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");}
	catch(e){
		try{xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");}
		catch(e){
			try{xmlhttp = new XMLHttpRequest();}
			catch(e){
				xmlhttp = false;
			}
		}
	}
	if (!xmlhttp) 
			return null;
		else
			return xmlhttp;
}