Hi Valerie
I agree with cyanide's comments, providing you have the necessary permissions set for the Perl script (guestbook.pl) there shouldn't really be a problem. The form method definitely needs to be set to
Post (code snippet from Matts Script archive below)
Code:
<form method=POST action="http://your.host.com/cgi-bin/guestbook.pl">
Your Name:<input type=text name=realname size=30>
E-Mail: <input type=text name=username size=40>
Hope this helps, and let us know how you get on!
Paul