pusing

---view form login--
<form id="loginForm" action="index/login_pelamar" method='POST'>
                        <fieldset id="body">
                            <fieldset>
                                <label for="email">Username</label>
                                <input type="text" name="username" id="username" />
                            </fieldset>
                            <fieldset>
                                <label for="password">Password</label>
                                <input type="password" name="password" id="password" />
                            </fieldset>
                            <input type="submit" id="login" value="Sign in" />
                            <label for="checkbox"><input type="checkbox" id="checkbox" />Remember me</label>
                        </fieldset>
                        <span><a href="#">Forgot your password?</a></span>
                    </form>

--controller index----
function login_pelamar(){
        $nama = $_POST['username'];
        $pass   = $_POST['password'];
        $this->load->model('register_model');
        $query = $this->register_model->login($nama,$pass);
            if($query->num_rows > 0){
                $user_row =$query->result();
                $user = $user_row[0];
                $array_session = array(
                                        'sudah_login_pelamar' => TRUE,
                                        'username' => $user->username,
                                        'id_pelamar' => $user->id_pelamar
                                        );

            $this->session->set_userdata($array_session);
            redirect('halamanpelamar');
        }else{
            redirect('index/index');
            }
    }

---register_model---
function login($nama,$pass)
    {
        $this->session->userdata('username','$nama');
        $this->db->where(array('username' => $nama, 'password' => md5($pass)));
        return $this->db->get('pelamar');
    }

---controller halamanpelamar-----
function index() {
        if($this->session->userdata('sudah_login_pelamar')){
        $this->load->view('menu');
        }
    }