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) {
        Home_Over = newImage("images/Home-over.gif");
        Services_Over = newImage("images/Services-over.gif");
        Portfolio_Over = newImage("images/Portfolio-over.gif");
        Support_Over = newImage("images/Support-over.gif");
        ContactUs_Over = newImage("images/ContactUs-over.gif");
        preloadFlag = true;
    }
}