// Preload
buttopover = new Image ();
buttopover.src = "/images/but_top-over.gif";
buttlinkover = new Image ();
buttlinkover.src = "/images/but_link-over.gif";
buttbackover = new Image ();
buttbackover.src = "/images/but_back-over.gif";
// Functions
function myChangeImg(aName, aUrl, aText) {
    document.images[aName].src = aUrl;
    window.status = aText;
};