function Abfrage(frage, url)
  {
    if (confirm(frage)) {
      location.href=url;
    }
  }

  function LayerDisplay(id, mode)
  {
    if (mode == 'show') {
      document.getElementById(id).style.display = 'block';
    } else {
      document.getElementById(id).style.display = 'none';
    }
  }
  
  function CloseAllLayers()
  {
    LayerDisplay("FLUG","");
    LayerDisplay("HOTEL","");
    LayerDisplay("MIETWAGEN","");
    LayerDisplay("BUECHER","");
  }