if(!empty($category_new)) {
    $query = 'INSERT INTO category (name) VALUES ("'.mysql_real_escape_string($category_new).'");';
    $mysql->execute($query);
    if(isset($_POST['new_category']) && $_POST['new_category'] == 1) {
        $query = 'SELECT id FROM category WHERE name = "'.mysql_real_escape_string($category_new).'" ORDER BY id desc LIMIT 1;';
        $result = $mysql->execute($query);
        if($row = mysql_fetch_object($result)) {
            $newcatid = $row->id;
            $query = 'INSERT INTO `game_category` (`game`, `category`) VALUES ('.$object.', '.$newcatid.');';
            $mysql->execute($query);
        }
    }
}