function newImage(arg) {
        if (document.images) {
            rslt = new Image();
            rslt.src = arg;
            return rslt;
        }
    }
    
    function changeImages() {
        if (document.images && (preloadFlag == true)) {
            for (var i=0; i<changeImages.arguments.length; i+=2) {
                document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
            }
        }
    }
    
    var preloadFlag = false;
    function preloadImages() {
        if (document.images) {
		nav_interiors_over = newImage("images/nav_interiors-over.gif");
		nav_stilllife_over = newImage("images/nav_stilllife-over.gif");
		nav_kids_over = newImage("images/nav_kids-over.gif");
		nav_tearscovers_over = newImage("images/nav_tearscovers-over.gif");
		nav_clients_over = newImage("images/nav_clients-over.gif");
		nav_contact_over = newImage("images/nav_contact-over.gif");
        preloadFlag = true;
        }
    }