var BuchungsFenster = null;
function go() {
  if ( BuchungsFenster == null ) {
    BuchungsFenster = window.open( '', 'Buchungsanfrage', 'toolbar=no, width=750, height=550, directories=no, status=yes, scrollbars=yes, resize=yes, menubar=no');
  } 
  else 
  {
    if ( BuchungsFenster.closed ) {
      BuchungsFenster = window.open('', 'Buchungsanfrage', 'toolbar=no, width=750, height=550, directories=no, status=yes, scrollbars=yes, resize=yes, menubar=no');
    } else {
      BuchungsFenster.focus(); }
    }
document.bkrequest.target='Buchungsanfrage';
document.bkrequest.action='http://www.hoteldaten.com/koop-apis/wdba/dorequest.php';
document.bkrequest.submit();
document.bkrequest.target='_self';}