function preload() {
  Bild1 = new Image();
  Bild1.src = "fileadmin/templates/img/barcode.jpg";
  Bild2 = new Image();
  Bild2.src = "fileadmin/templates/img/unav_express2.gif";
  Bild3 = new Image();
  Bild3.src = "fileadmin/templates/img/unav_sonder2.gif";
  Bild4 = new Image();
  Bild4.src = "fileadmin/templates/img/unav_transporte2.gif";
  Bild5 = new Image();
  Bild5.src = "fileadmin/templates/img/unav_umzuege2.gif";
}