Problem with fetch_class() and redirect()

Hi everybody,
I've a little problem with fetch_class and redirect.
I'm using this two method in this way, in my core controller Admin_Controller:

PHP Code:

if (!$this->router->fetch_class() == 'login' && !$this->ion_auth->is_admin()) {
            $this->session->set_flashdata('message', 'You must be an admin to view this page');
            redirect('admin/login');
        } 


I'm trying to check if the user is an admin, else he will be redirected to the login page, but the login page share the same controller that extend MY_Controller. (Admin_Controller) So this code without the fetch_class() control would cause an infinite loop. But if i omit the fetch_class(), the redirect() work. I've tried everything but couldn't find out why this is happening :C
(Anyway, sorry for my poor english ><)

try this

PHP Code:

if ($this->router->fetch_class() != 'login' && !$this->ion_auth->is_admin()) 


Works perfectly, thanks!