So I (accidentally) discovered that I can link within different defined pages by using code like:

Code:
<a href="<?php echo zen_href_link(FILENAME_CONTACT_US); ?>">Contact Us</a>
and just replacing CONTACT_US with like CONDITIONS or PAGE_2 or PAGE_3 or whatever. But, this doesn't seem to work outside of these set of defined pages. Is there a proper way to link within my site?

For example, let's say within one of my product descriptions, I'd like to have a link that says "Tell me about this" which links to PAGE_2. Right now, I'm having to use a hard-coded link, like:

Code:
<a href="http://mysite.com/zencart/index.php?main_page=page_2">Tell me about this</a>
But I'm sure there has to be a better / more correct way of doing this. I tried using the php echo command, which works within all the define_xxx pages, but not outside of there (such as inside product descriptions).