prova cosi
puoi stampa la variabile $n_crediti.Codice PHP:
$user =& JFactory::getUser();
$uid = $user->id;
$db_user=&JFactory::getDBO();
$query_user = 'SELECT crediti FROM #__users WHERE id = '.$uid;
$db_user->setQuery( $query_user);
$db_user->query();
$n_crediti = $db_user->loadResult();