up1 = new Image();
up1.src = "../images/up.gif";
up2 = new Image();
up2.src = "../images/up2.gif";

up1i = new Image();
up1i.src = "images/up.gif";
up2i = new Image();
up2i.src = "images/up2.gif";

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