session_destroy not working please help if possible.

[eluser]noname525[/eluser]
vv

[eluser]InsiteFX[/eluser]

Code:

public function logout()
{
    $this->session->userdata = array();
    // or
    $data = array();
    $this->session->set_userdata($data);

    $this->session->sess_destroy();
    $url = base_url();
    redirect($url.'index.php/home', 'refresh');
}