controller codeigniter in ubuntu linux not run

[eluser]tusukgigi[/eluser]
hi,
i installed codeigniter in ubuntu linux with lampp.
when i point to localhost/codeigniter/home in my browser,

Not Found

The requested URL /codeigniter/home was not found on this server.

Code:

<?php

class Home extends Controller {

    function __Construct()
    {
        parent::Controller();    
    }
    
    function index()
    {
        //$this->load->view('welcome_message');
        echo "Hello home, I was here:D ";
    }
}

how to fix it.
(sorry for my english )