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) {
topic_menu_04_over = newImage("images/topic_menu_04-over.gif");
topic_menu_05_over = newImage("images/topic_menu_05-over.gif");
topic_menu_07_topic_menu_05_over = newImage("images/topic_menu_07-topic_menu_05.gif");
topic_menu_08_over = newImage("images/topic_menu_08-over.gif");
topic_menu_11_over = newImage("images/topic_menu_11-over.gif");
topic_menu_12_over = newImage("images/topic_menu_12-over.gif");
preloadFlag = true;
}
}

preloadImages();