/* Bildung des Request-Objektes */
function getHTTPReq() {
  var req_obj = null;
  if (window.XMLHttpRequest) {
    req_obj = new XMLHttpRequest();
  } else if (window.ActiveXObject){
    try {
      req_obj = new ActiveXObject('Msxml2.XMLHTTP');
    } catch(ex) {
      try {
        req_obj = new ActiveXObject('Microsoft.XMLHTTP');
      } catch(ex) {
      }
    } 
  }
  return req_obj
}