Custom rollover nav bar in Header.php ?

Hi.. I currently have a flash menu embedded in the header.php of my child theme. It all works brilliantly but I need to replace this menu with a simpler javascript menu . I have designed my menu in a div tag on a normal html page. Then i copied the complete div tag html, and pasted it in place of the flash object. When i do this the div tag appears correctly with its background, but all the rollover images appear very large and spill out over the rest of the page. the flash menu is in use at the moment at http://www.sativarecords.com/site/?page_id=292 . Alternatively is there away to use my own images in a wordpress rollover menu ? Thanks in advance.