function buchungsPlan(aYear)
{
  var theight = 500;
  var twidth = 600; 
 
  buchWin = window.open("","Buchungsplan", "width=" + twidth + ",height=" + theight);

  var hohe, breite;
  hoehe = screen.height;
  hoehe = (hoehe - theight- 50) / 2;
  breite = screen.width;
  breite = (breite - twidth) /2;
  buchWin.window.moveTo(breite ,hoehe);
  buchWin.location.href= "http://gamers-area.com/calendrier/calendrier.php";
  return;


}