Constructor error?

[eluser]Hamed[/eluser]
I use one of website tutorial and now I get error on constructor:


Fatal error: Call to undefined method CI_Controller::Controller() in C:\wamp\www\application\controllers\main.php on line 5

Code:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Main extends CI_Controller {
    public function Main() {
        parent::Controller();
    }
public function index()
{
    $query = $this->db->query('');
    $this->load->view('main/index');
}
}