var http_request = false;

function doRequest(url) {
	
	http_request = false;
	
	if (window.XMLHttpRequest) http_request = new XMLHttpRequest();
	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) return false;

	http_request.onreadystatechange = evalContents;
	http_request.open('GET', url, true);
	http_request.setRequestHeader("Pragma", "no-cache");
	http_request.setRequestHeader("Cache-Control", "must-revalidate");
	http_request.setRequestHeader("If-Modified-Since", document.lastModified);
	http_request.send(null);

}

function evalContents() {

	if (http_request.readyState == 4)
       	if (http_request.status == 200)
					eval(http_request.responseText);

}