php - Session in codeigniter not working well -

i can't figure out what's actual error session in codeigniter. other project working code. in case, got problem.

for login session code is:

 $data = array(                'username' => $this->input->post('username'),                'admin_logged_in' => true,                'logged_in' =>true               );  $this->session->set_userdata($data); 

and check session as:

 if ($this->session->userdata('admin_logged_in') == true) {       // code     } 

before going controller checking session above , if session not true redirecting login page.

for logout:

 function logout() {         if ($this->session->userdata('admin_logged_in') == true) {             $useremail = $this->session->userdata('username');         $data = array(                 'username' => $useremail,                 'admin_logged_in' => true,                 'logged_in' =>true             );         $this->session->unset_userdata($data);         $this->session->sess_destroy();         redirect('login');      }   } 

but above code not working me. when logout, page redirected logout page session not destroyed since can access page needs session set. please me.

updated

i got strange problem. when log system , logout. , trying access method needs session. can access if wrote method name without index.php. , cannot access method needs session if wrote method name index.php. example: bnw needs session set in order go furthur. if login , logout then, if write in borwser url following:

 example.com/index.php/bnw      //it redirects login page.  example.com/bnw                //it logs in directly. 

• does removing index.php .htaccess gives problem session?

put inside logout function, works me

$user_data = $this->session->all_userdata();         foreach ($user_data $key => $value) {             if ($key != 'session_id' && $key != 'ip_address' && $key != 'user_agent' && $key != 'last_activity') {                 $this->session->unset_userdata($key);             }         }     $this->session->sess_destroy();