public function set_user($network_id, $user_id)
 {
     $this->network = FALSE;
     $this->user = FALSE;
     $n = new network();
     if (!$n->LOAD_by_id($network_id)) {
         return FALSE;
     }
     if (!($u = $n->get_user_by_id($user_id))) {
         return FALSE;
     }
     $this->network = $n;
     $this->user = $u;
     return TRUE;
 }