Getting the file a PHP script is called from

As a beginner to PHP4, I wrote a simple logging program (since my server does not have the best logging functionality) to track where users go on my website. The way I am implementing it is by including it as a <! --#include virtual="myphpscript.php" --> inside another include file, the footer to all of my pages so, it works out like this: HTML Page -> Included footer -> Included PHP script Now, the HTTP_ENV_VARS work fine even in this setup, and return HTTP_REFERRER correctly as the page I visited before coming to the current page. But that is not what I want. I would like a way, without putting the php script inside my HTML files, to be able to determine what page called the script. Any help would be appreciated! Thanks