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) {
        indexnav_03_news_over = newImage("images/indexnav_03-news_over.gif");
        news_resource_over = newImage("images/news-resource_over.gif");
        news_over = newImage("images/news-over.gif");
        resource_news_over = newImage("images/resource-news_over.gif");
        resource_over = newImage("images/resource-over.gif");
        spot_news_over = newImage("images/spot-news_over.gif");
        spot_over = newImage("images/spot-over.gif");
        members_news_over = newImage("images/members-news_over.gif");
        members_over = newImage("images/members-over.gif");
        events_news_over = newImage("images/events-news_over.gif");
        events_over = newImage("images/events-over.gif");
        join_over = newImage("images/join-over.gif");
        join_news_over = newImage("images/join-news_over.gif");
        preloadFlag = true;
    }
}


<!-- End Preload Script -->