function FensterOeffnen (Adresse) {
  MeinFenster = window.open(Adresse, "Zweitfenster", "width=730,height=700,left=100,top=100");
  MeinFenster.focus();
}

button_img1 = new Image();
button_img1.src = "container/images/b_dark_Hauptseite.gif";
button_img2 = new Image();
button_img2.src = "container/images/b_bright_Hauptseite.gif";

function change( name, object )
{
  window.document.images[name].src = object.src;
}