var filename ;
filename = location.href.substring((location.href.lastIndexOf("/")) + 1, location.href.length) + "?act=ajax";
var xmlhttp;
function getXmlhttp()
{
	var http_request;
	
	if(window.XMLHttpRequest) { 
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			http_request.overrideMimeType("text/xml");
		}
	}
	else if (window.ActiveXObject) { 
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}
	if (!http_request) { 
		window.alert("can't create XMLHttpRequest object.");
		return null;
	}	
	return http_request;
}