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) {
top_04_over = newImage("img/top_04-over.gif");
top_07_over = newImage("img/top_07-over.gif");
top_09_over = newImage("img/top_09-over.gif");
top_10_top_09_over = newImage("img/top_10-top_09_over.gif");
top_10_top_11_over = newImage("img/top_10-top_11_over.gif");
top_11_over = newImage("img/top_11-over.gif");
top_14_over = newImage("img/top_14-over.gif");
top_15_top_14_over = newImage("img/top_15-top_14_over.gif");
top_17_over = newImage("img/top_17-over.gif");
top_20_over = newImage("img/top_20-over.gif");
preloadFlag = true;
}
}