unable to call controller from URL

[eluser]yaswanthbs[/eluser]

Code:

<?php

class User extends CI_Controller {

function index() {
  $this->load->view('login');
}

function userlogin() {
  echo 'user [size=1][/size]is logged in';
}

}
?>

This is my code and I am unable to call User controller. When I am accessing like this
http://localhost/learning/User

I am getting error as Not Found
The requested URL /learning/User was not found on this server.

Please help me..