Problems with PHP code & meta tags?

Question

There's this e-commerce website. The index page is entirely in PHP. All of the products are generated from the index page. When I add XHTML meta tags to the index page, it changes the meta tags on the other pages as well.

What do I need to do to prevent this?

Answer 1

are the product pages generated and based within the php from the index page?

if its as if the products are embedded within the original page then surly the meta tags will be surrounding the php code (the product), working like the include(); tag....