Session Help :(

[eluser]Unknown[/eluser]
Hello guys, I need your help >.< my session is not working can you check my code and slap me. I already load the session library but still not working...

Code:

function login()
{  
  $this->load->library('form_validation');

  $this->form_validation->set_rules('email', 'Email Address', 'trim|required|valid_email|xss_clean');
  $this->form_validation->set_rules('password', 'Password', 'trim|required|min_length[6]|xss_clean');
  if($this->form_validation->run()== FALSE)
  {
   $data['main_content'] = 'pages/login_page';
   $this->load->view('includes/template', $data);
  }
  else
  {
   $this->load->model('membership_model');
   $query = $this->membership_model->validate();
    if($query)
    {
     $data = array('email' => $this->input->post('email'), 'is_logged_in' => TRUE);
     $this->session->set_userdata($data);
     redirect('site/members_area');
    }
    else
    {
     $this->no_record();
    }
  }

thanks...