normal1 = new Image();
         normal1.src = "images/navi_button_gruen.gif";        /* Standard-Grafik */
         highlight1 = new Image();
         highlight1.src = "images/navi_button_gelb.gif";      /* Highlight-Grafik */

function switch_button (Bildnr,Bildobjekt) {
         window.document.images[Bildnr].src = Bildobjekt.src;

return true;
}