You can do a couple of things. First, you can go to your log files. This is where the STDERR output gets directed when working with CGI. So all the error messages can be seen there. What you can also do is redirect the error messages to appear in your browser. Check out the cgi::carp module. Come back if you have other questions.

$PM = "Perl Monk's";
$MCF = "Most Clueless Friar Abbot Bishop";
$nysus = $PM . $MCF;
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