function FensterOeffnen(adr, nwidth, nheight) {
  var wwidth = '600';
  var wheight = '600';
  if (nwidth) { wwidth = '' + nwidth; }
  if (nheight) { wheight = '' + nheight; }
  var winparam = "width=" + wwidth + ",height=" + wheight + ", scrollbars=yes,resizable=yes";
  MyFenster = window.open(adr, "secondary", winparam); /* ,left=10,top=20 */
  MyFenster.focus();
}