add graphic to Navigationheader text

[rlang]

I am trying to find a way to add an image as a background to each item in the Navigation header instead of just seeing the words "Top" "Catalog" etc. I've tried stylesheet and some changes to Header.php with no real success. I've even been able to add an image (shell) to the Navigition Header but it is next to the text.

 

 

Is there a solution to this idea.

http://sandandwaves.com/catalog//catalog/index.php

 

thanks.