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_04_over = newImage("images/nav_04-over.jpg");
                nav_05_nav_04_over = newImage("images/nav_05-nav_04_over.jpg");
                nav_05_over = newImage("images/nav_05-over.jpg");
                nav_06_nav_05_over = newImage("images/nav_06-nav_05_over.jpg");
                nav_06_over = newImage("images/nav_06-over.jpg");
                nav_07_nav_06_over = newImage("images/nav_07-nav_06_over.jpg");
                nav_07_over = newImage("images/nav_07-over.jpg");
                nav_08_nav_07_over = newImage("images/nav_08-nav_07_over.jpg");
                nav_08_over = newImage("images/nav_08-over.jpg");
                nav_09_nav_08_over = newImage("images/nav_09-nav_08_over.jpg");
                nav_09_over = newImage("images/nav_09-over.jpg");
                nav_10_nav_09_over = newImage("images/nav_10-nav_09_over.jpg");
                nav_10_over = newImage("images/nav_10-over.jpg");
                nav_11_nav_10_over = newImage("images/nav_11-nav_10_over.jpg");
                nav_11_over = newImage("images/nav_11-over.jpg");
                nav_12_nav_11_over = newImage("images/nav_12-nav_11_over.jpg");
                nav_12_over = newImage("images/nav_12-over.jpg");
                nav_13_nav_12_over = newImage("images/nav_13-nav_12_over.jpg");
                nav_13_over = newImage("images/nav_13-over.jpg");
                nav_15_nav_13_over = newImage("images/nav_15-nav_13_over.jpg");
                nav_15_over = newImage("images/nav_15-over.jpg");
                preloadFlag = true;
        }
}