public function execute()
{
$this->doAction();
if (isset($_GET['forum_id'])) {
$forum_id = $_GET['forum_id'];
$this->forum = DbForum::GetById($forum_id);
if (!$this->forum->isNull()) {
$this->topics = DbTopic::GetByForum($forum_id);
} else {
header('location: forums.php');
}
} else {
header('location: forums.php');
}
}