legrand,
A .pl is a PERL script. Perl scripts usually need to be within the cgi-bin subfolder. Please note as well, depending on your server it may not parse the ".pl" extension, you may need to use ".cgi".
This is the case with the host that I use, so you may need to rename the file.
Also, check the permissions on the file, it should be 0755 - Which is User: Read, Write, Execute, others: Read and Execute.
I hope this helps..