my $logged_in = write_session( $user );

print Dumper($logged_in, $session->param('user'));


sub write_session {
   my $user = shift;

   my $session = new CGI::Session();

   $session->param('user'        => $user);
   $session->param('logged_in'   => 1);

   my $cookie = $query->cookie( CGISESSID => $session->id );
   #print $query->header(-cookie => $cookie);
   print $session->header(-cookie => $cookie);

   #$session->flush()
   return ($session->param('logged_in'));
}

---------- DUMPER ------------
$VAR1 = 1;
$VAR2 = undef;