function getXMLHttpRequest()
{
  if (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('Nem tudom létrehozni a XMLHTTP példányt!');
      return false;
  }

  //http_request.onreadystatechange = function() { myret(http_request); };

  return http_request;

}