Problem with sessions on multiple installations

[eluser]1234qwer[/eluser]
About the sessions, ¿Do I put the physical path? something like:


$route['logout'] = "dir\system\application\controllers\administrator.php\logout";

Because in administrator.php I have the following function:

function logout()
{
$this->session->sess_destroy();
$this->load->view('admin/login');
}

Am I right? or instead of:
$route['logout'] = "dir\system\application\controllers\administrator.php\logout";

I must put:

$route['logout'] = "http://www.mysite.com/modulename/index.php/administrator/perform_logout";

????