var http_request = false;

function makeRequest(url) {

	http_request = false;
	
	brVer = navigator.userAgent;
    isIE = brVer.indexOf('MSIE') != -1;
	
	if( (!isIE) && window.XMLHttpRequest) { // Mozilla, Safari,...
				http_request = new XMLHttpRequest();
				if (http_request.overrideMimeType) {
					  http_request.overrideMimeType("text/xml");

				}
		  } else if (window.ActiveXObject) { // IE
				try {
					  http_request = new ActiveXObject("Msxml2.XMLHTTP");
				} catch (e) {
					  try {
					  http_request = new ActiveXObject("Microsoft.XMLHTTP");
					  } catch (e) {}
				}
		  }

		  if (!http_request) {
				alert("Poddaje sie :( Nie moge stworzyc instancji obiektu XMLHTTP");
				return false;
	}
	http_request.onreadystatechange = function() {
			alertContents(http_request); 
		};
	
	http_request.open("GET", url, true);
	http_request.send( null );
}