CodeIgniter仅为管理员区域加载帮助程序，语言和库

This has been asked a few times and I have seen tutorials yet i failed to do it. I basically have abc.com/admin then admin/controllers. What I need is to load some languages, helpers and libraries for admin area.

    class MY_Controller extends CI_Controller{         

        function __construct(){
          parent::__construct();
          }

      }


    class Admin_Controller extends MY_Controller{
         function __construct(){
          parent::__construct();
          file_put_contents('trial.txt','trial data');                 //JUST TO SEE IF THAT EVEN WORKS and it is not writing the file either
        $this->lang->load('scripts','english');
   }
}

Nothing is loaded in all Admin areas, unless I autoload them in autoload.php. What am I missing?