Preload rollovers

[blackgem]

OK,

So I've replaced the standard navbar with image buttons [jpegs] for the navigation on my forum, I'm using rollovers images. Is there a way to make the onMouseOver images preload, so there isn't that delay when you hover over them the first time?

On static html pages, I guess you would use a javascript but I haven't been able to get these working [I've placed the script in the headerinclude, still no luck]. Is there an alternative way to preload them or is there something I am missing? [or do I just have a dodgy script :|]

Thanks.

Edit: It was just a dodgy script after all, well dodgy on my part, using absolute paths for the images fixed it up.