use CGI qw/:standard/;

$modtime = scalar(gmtime(time - (3600 * 8))) . " GMT";
$exptime = scalar(gmtime) . " GMT";

print header(-expires=>$exptime, 'last-modified'=>$modtime,
             'cache-control'=>"no-cache, must-revalidate",
             'pragma'=>"no-cache"),
start_html('Header Test'),
pre("\nModtime: $modtime\nExptime: $exptime\n"),
end_html;