I can't agree with my learned colleagues more, you should use strict; use CGI; and set the -w flag.

Another thing to do however, is to switch taint checks on and scrub your data clean (detaint). Your CGI-BIN is a gaping hole in your server's defences against the world, and if you put something in there, especially something that writes to the disk system, you sould make sure that you know what it's writing and where. You can't trust the users not to add something nasty inside a form.

Please read perlsec, to see why -T is a good idea. At best a inocent mistake could mess up your array, at worst they could format your hard disk....