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) {
about_over = newImage("i/c/about_over.jpg");
products_over = newImage("i/c/products_over.jpg");
order_over = newImage("i/c/order_over.jpg");
contactus_over = newImage("i/c/contactus_over.jpg");
preloadFlag = true;
}
}