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) {
id7_over = newImage("images/7-over.gif");
id8_over = newImage("images/8-over.gif");
id9_over = newImage("images/9-over.gif");
id10_over = newImage("images/10-over.gif");
id11_over = newImage("images/11-over.gif");
id12_over = newImage("images/12-over.gif");
preloadFlag = true;
}
}