function kwkQuizWindow() {
  kwk_quiz_win = window.open('http://www.kwk-modellstadt-berlin.de/kwk-energie-quiz.php',"Quiz","directories=no,location=no,menubar=no,status=no,top=20,left="+(screen.availWidth-800)/2+",scrollbars=no,resizable=no,width=800,height=600");
  kwk_quiz_win.focus();
 }