sub main {

  my %dispatch = (
    upload  => \&upload,
    debug   => \&debug,
    DEFAULT => \&upload,
  );

  $draw->headers();
  $draw->html_start( { title => $title } );

  my $action = $cgi->param('action') || 'DEFAULT';
  my $do_sub = $dispatch{ $action };

  if ( $do_sub ) {
    &$do_sub();
  } else {
    warn "[warn] Invalid action: [$action]";
    die "[die] You can't make me do that!\n";
  }

  $draw->html_end();
}