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) {
                siterough_04_over = newImage("images/nav/siterough_04-over.gif");
                siterough_05_siterough_04_over = newImage("images/nav/siterough_05-siterough_04_o.gif");
                siterough_06_over = newImage("images/nav/siterough_06-over.gif");
                siterough_07_siterough_06_over = newImage("images/nav/siterough_07-siterough_06_o.gif");
                siterough_08_over = newImage("images/nav/siterough_08-over.gif");
                siterough_10_over = newImage("images/nav/siterough_10-over.gif");
                siterough_11_siterough_10_over = newImage("images/nav/siterough_11-siterough_10_o.gif");
                siterough_11_siterough_12_over = newImage("images/nav/siterough_11-siterough_12_o.gif");
                siterough_12_over = newImage("images/nav/siterough_12-over.gif");
                preloadFlag = true;
            }
        }