Replace TEXT nav menu with BUTTON

I just changed skins on our site. The new skin has a menu with a small picture next to the text for the button. When I go into the admin panel and try to upload a button or different pic, the new button is reduced in size and placed next to the text that is not replaced. (ie Home, Calendar, etc.).
I am using a phpBB2 skin that does not give me a CSS sheet to work with like my last skin. I would really like to change the nav menu to a "button" style menu.
Any help is appreciated.
Website can be seen at http://www.oasclan.com/

GO to Admin CP > Display > Headers & Navigation...
Display only images in the link bar : 'Yes'
Click 'Save'

Hey! Thanks for the quick reply. Sure enough, that is where my problem was! Guess this can be considered solved.