return insert id from database insert function

now, how to return insertID from this function?!

PHP Code:

public function insertAlbumData(array $data)
{
   $this->db->table('gallery_albums')
         ->insert($data);
   return $this->db->insertID();
} 


You can see things I made with codeigniter here: itart.pro its not overly impressive as I have very little time to learn.