public function erase()
 {
     $idArticulo = $this->Id;
     $ok = parent::erase();
     if ($ok) {
         // Borrar las tarifas
         $tarifas = new Tarifas();
         $tarifas->queryDelete("IdArticulo='{$idArticulo}'");
         unset($tarifas);
     }
     return $ok;
 }