Login script not functioning

[eluser]Unknown[/eluser]
I have just implemented a login script and it doesn't seem to work i dont not know it seems to be going wrong in the code

i've got my login controller which does the following

login.php

Code:

class login extends CI_Controller {

    function index(){

        $data['maincontent'] = 'login_form';
        $this->load->view('includes/template', $data);


    }

    function validate_credentials(){

        $this->load->model('membership_model');
        $query = $this->membership_model->validate();

        if($query){

            $data = array(
                'username' => $this->input->post('username'),
                'is_logged_in' => true
            );

            $this->session->set_userdata($data);
            redirect(site/members_area);

        }

        else{
            $this->index();

        }



    }

}

i've my model which accesses the database with no problems

membership_model.php

Code:

class Membership_model extends CI_Model {

    function validate(){
        $query = $this->db->get("membership");
        //retrieve all records where username equals to typed in username value
        //retrieve all records where password equals to typed in password value
        $this->db->where('username', $this->input->post('username'));
        $this->db->where('password', md5($this->input->post('password')));


        if($query->num_rows == 1){

            return true;
        }




}

my config folder has got the following

details

config.php

Code:

$config['base_url'] = 'http://localhost/ci_demo';
$config['encryption_key'] = 'sholly';

autoload.php

Code:

$autoload['model'] = array('membership_model');
$autoload['helper'] = array('url', 'form');
$autoload['libraries'] = array('database', 'session');

route.php

Code:

$route['default_controller'] = "login";

Any help please

[eluser]Unknown[/eluser]
never mind i have just realised my mistake which is in my login controller

Code:

redirect(site/members_area);

which should be placed in single quotes and replaced with the following

Code:

redirect('site/members_area');

silly mistake on my part, it all working now