$title = $_POST["title"];
$isbn = $_POST["isbn"];
$autor = $_POST["autor"];
$genre = $_POST["genre"];
$release = $_POST["release"];
$res = $bk->add($title, $isbn, $autor, $genre, $release);
if ($res) {
$response->res = true;
$response->mes = $mes->get_msg("e004");
} else {
$response->res = false;
$response->mes = $mes->get_msg("e003");
}
break;
case 'list':
$res = $bk->display_list();
if ($res) {
$response->res = true;
$response->mes = $res;
} else {
$response->res = false;
$response->mes = $mes->get_msg("e005");
}
break;
case 'delete':
$id = $_POST['id'];
$res = $bk->del_item($id);
if ($res) {
$response->res = true;
$response->mes = $mes->get_msg("e006");
} else {
