The code you gave is fine, so I suspect it is either a permissions or configuration problem.

Generally when debugging CGI problems it helps to examine the web server's error logs so that you can see what the error message is. Attempting to debug problems like this without having access to error messages will be very difficult (arguably impossible for a novice).

In a pinch, in the absense of log file access, this could help you considerably:

use CGI::Carp 'fatalsToBrowser';
[download]