function Impress() {
  adress = 'http://www.12app.com/Impresum.php';
  if ((PopUpWindow == false)||(PopUpWindow.closed == true)){
    PopUpWindow = window.open(adress, "PopUpWindow", "width=450,height=350,left=50,top=50,location=no;menubar=no,resizable=no,scrollbars=yes,status=no,toolbar=no");
    PopUpWindow.focus();
  }
  else{
    PopUpWindow.close();
    PopUpWindow = false;
    setTimeout('Impress()', 50);
  }
return
}