var base_dir = "/images/nav/";
var imgs = new Array('availablenow-over.gif','cruiseads-over.gif','freepersonals-over.gif','readreviews-over.gif','search-over.gif','chat-over.gif');
                for (var i=0; i < imgs.length; i++) {
                var img = new Image();
                img.src = base_dir + imgs[i];
                }
        
        function rollover(name1,img1){
                document.images[name1].src = base_dir + img1;
                }