Add to Cart CSS Image Rollovers

I'm hoping this hasn't already been addressed, though I have been searching the forums to find out. :wacko:

I am in tpl_product_info_display and I'm trying to find where the add to cart button code is defined. I am wanting to style the button so I can use my own graphic button that has three states contained within one image. Using CSS, you can set the background image of a tag and then move the image so that the over and active states are visible. Apple.com uses this extensively. However, I can't find where the code of the Add to Cart button is defined. Anyone know?

Thanks! :)

Christian

As an addendum to my post, I found definitions for form submit buttons with images under zen_image_submit in includes/functions/html_output.php but there's another function called by tpl_product_info_display.php to zen_get_buy_now_button in includes/functions/functions_general.php that seems to have no effect because when I took it out and just displayed the button sent back from zen_image_submit, there was no change. A bit confused on that one. Probably beyond my tinkering-level knowledge but hoping to get my css image rollovers for submit buttons. If I can standardize in some way, even better.

Just in case anyone else is interested in my hack solution, I put class="submitButton" into the <input type="image"> component of zen_image_submit within includes/functions/html_output. I'm disappointed that I couldn't do a template override within the functions folder. Though, I guess it's not really a template. Still, it would be nice to be able to have more control over these submit buttons. :)

this was very helpful..thanks