function openCentered(URL)
    {
      breite = 1000 
      hoehe  = 680
      var PopupX = (screen.availWidth / 2) - (breite / 2);
      var PopupY = (screen.availHeight / 2) - (hoehe / 2);
      window.open("http://www.uni-lueneburg.de/privatgast/privat/kiesow/Bildergalerie/" + URL + "/frame.htm", "Bildansicht", "resizable=yes, width=" + breite + ", height=" + hoehe + ", left=" + PopupX + ", top=" + PopupY);
    }

function openArchiv(URL)
    {
      breite = 800 
      hoehe  = 600
      var PopupX = (screen.availWidth / 2) - (breite / 2);
      var PopupY = (screen.availHeight / 2) - (hoehe / 2);
      window.open("../Ergebnisse/Archiv/" + URL + ".htm", "Archivansicht", "resizable=yes, scrollbars=yes, width=" + breite + ", height=" + hoehe + ", left=" + PopupX + ", top=" + PopupY);
    }