passing variables to scripts

(yes, newbie - but I *have* tried everything I know, I swear) I'm trying to write a "comments" system for my site (because I think I can). Basically, the script receives the ID of a particular entry (the site is a blog) via "?entry_id=<entry_id>". It checks to see if there's a corresponding text file (<entry_id>.txt) and if so, it prints the contents of the text file and invites the user to input a comment. If not, it prints "no comments" and invites the user... yadda yadda. Now, unless I'm mistaken, passing the arguments are done like so: http://www.foo.com/comments.php?entry_id=test Right? Unfortunately, it doesn't work. That is to say, everything about the script works, except recognition of the $entry_id variable. Something as simple as: <title>comments for entry "<?php echo("$entry_id"); ?>"</title> returns "<title>comments for entry ""</title>. Saving the text file's URL to a variable: <?php $filename = http://www.foo.com/$entry_id; .txt; ?> Doesn't work either. I had a semi-hunch (brought on by my own inexperience, no doubt) that maybe I had to start a session or something on the referring page. Tried that (session_start();), didn't have any effect. Bah. Can anyone point out what I'm doing wrong? TIA -- Mark Gallagher