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) {
menu_pro_over = newImage("top/menu_pro-over.gif");
menu_proinfo_over = newImage("top/menu_proinfo-over.gif");
menu_order_over = newImage("top/menu_order-over.gif");
menu_aboutus_over = newImage("top/menu_aboutus-over.gif");
menu_member_over = newImage("top/menu_member-over.gif");
menu_bbs_over = newImage("top/menu_bbs-over.gif");
preloadFlag = true;
}
}