I have a Perl action page that works but cant seem to get the redirect to work if someone refreshes the page. If someone copies the URL address of the Perl action page and puts it in another browser address window it does redirect the page.

Please advise how I can make the perl action page redirect on refresh? My attempt:

# $subject variable is coming from the form page
my $site_url = 'http://myurl/index.pl';
my $thequery = new CGI;
unless(defined($subject))
{
     print $thequery -> redirect($site_url);
     exit(0);
}