function GetXMLHttpRequest() {
  var http_request = false;

    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) {
      return false;
    }
	return http_request;
}