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_ro = newImage("images/dr-nav-about-ro.gif");
gallery_ro = newImage("images/dr-nav-gallery-ro.gif");
music_ro = newImage("images/dr-nav-music-ro.gif");
shop_ro = newImage("images/dr-nav-shop-ro.gif");
contact_ro = newImage("images/dr-nav-contact-ro.gif");
preloadFlag = true;
}
}