Indeed, it is untested code. I wrote it in August when I started learning Perl. It was the "two people" situation, which you mentioned, that made me put off using it on my site's guestbook even though I don't think that such a problem could appear on a low-volume site like mine.

As far as the checksuming bot is concerned... Man, you, older monks are masters in scrutiny! An amateur like me would never have imagined anything like that... Well, that's why I'd better stick with my current job as a high school teacher. ;-)

Anyway, that's how far my limited experience with Perl managed to get me. Last week, I ordered Programming Perl. So, hopefully, once I've read it, I will be able to build on the code above and come up with a more comprehensive solution in the near future.

Thanks for the pointers!