$pass is your password. If you do not enter the string $pass expects, the script will exit. If your script is located in the foo directory and called bar.cgi, you need to use a query string something like http://yoursite/foo/bar.cgi?pass=Tn9SG0s except, now that everone on this site knows that is your password, you should change it to something else in the script and use that to call the script.

I would also suggest that your friend is not as great a programmer as you might think because the script does not use warnings or strict and neglects to check if there's anything in the pass parameter at all.