Problems with the native session

[eluser]Zorancho[/eluser]
I will do all of it with the CI Sessions.. but this is how my controller looks like
<?php if(!defined('BASEPATH')) exit('No direct script access allowed');

class MY_Controller extends Controller
{
public function MY_Controller()
{
parent::__construct();
}

public function destroy_sess()
{
$this->session->sess_destroy();
unset($_SESSION['userid']);
unset($_SESSION['logged_in']);
unset($_SESSION['role']);
redirect('servis/');
}
}