Need help with a PHP script using the: .php?blahblahblah

Ok, I have this page on my site such as:

http://www.site.com/dwnldguide.php

I am selling a digital product on ebay, I then email them a link to download the product on my website. This is the link I give them:

http://www.site.com/dwnldguide.php?ebayuser=accountname

Where "accountname" is the ebay user's accountname that I manually put in there.

The download page is pretty generic and simply just has a raw link to the downloadable product. All I want that PHP file (dwnldguide.php) to do is simply take that variable after the "?" and simply put it into the html page at a certain spot. Which the end result will look something like this:

This product is registered to the "ebayuser=accountname" and any attempt at piracy will be monitored blah blah blah... Download the Product Here!.... thanks for the purchase... etc..

This is ONLY a scare tactic, just to make them not distribute the link to anyone. I know this is not 100% secure, but Im just using this as an extra measure.

So can anybody make me this simple php script? Thanks for any help!!

 

Does this help?

This product is registered to <?PHP echo $_GET['ebayuser']; ?>

PHP:

 

if register globals is off solidphp's solution is very good.

If globals are on it simply enough to write <? echo $ebayuser; ?>

But it's recommended to use the first solution

 

more secure:

<?php 
(isset($_GET['ebayuser']) && $_GET['ebayuser'] !== '') 
? echo trim(preg_replace("/[^\x20-\xFF]/",'', $_GET['ebayuser'])) 
: echo 'undefined'; 
?>

Code (markup):