@Override
 public void onUpdate() {
   KeyboardListener kbl = this.getScreenFactory().getGame().getKeyboardListener();
   if (kbl.isOnPress("btn_ESC") && tickcounter == 0) // ESC button
   {
     Button b = new Button("Zurueck", false, false);
     b.addActionListener(this);
     b.callActions();
   }
   if (tickcounter != 0) {
     tickcounter--;
   }
   super.onUpdate(); // updating Gui Elements
 }