function logout()
 {
     $user_login_status_model = new User_model();
     $user_service = new User_service();
     $user_login_status_model->set_is_online('N');
     $user_login_status_model->set_user_id($this->session->userdata('USER_ID'));
     $user_service->update_online_status($user_login_status_model);
     $this->session->sess_destroy();
     redirect(site_url() . '/login/login_controller');
 }