How does "Show block only for specific content type" this section of code use in Drupal5.0?

How does "Show block only for specific content type" this section of code use in Drupal5.0?

Show block only for specific content type:

$match = FALSE;
$types = array('story' => 1, 'page' => 1);
if (arg(0) == 'node' && is_numeric(arg(1))) {
  $nid = arg(1);
  $node = node_load(array('nid' => $nid));
  $type = $node->type;
  if (isset($types[$type])) {
    $match = TRUE;
  }
}
return $match;

Waits for your reply,Thanks!