Question about product detail pages

This is something I'd like to do but don't have to at this point. As an example:

products_detail.php?ProductID=31

Nice format, decent layout. In general I'm happy with the HTML code generated by the PHP script. What I'd like to know is if it's possible to use a "floatbox" javascript call (same as the lightbox javascript you are using) or "lightbox" embedded with your product to hot link the large photo at the end of the long description so when the end user click on the hot link assigned to the image I've placed in the post it will call the javascript class and "float" in a popup window a larger image? Is it difficult to edit the PHP that generates the HTML to include the javascript call and where would I find the PHP code that's generating the product detail pages?

~Kim