CI total newbie topic

[eluser]keevitaja[/eluser]
how to access CI libraries from my custom library?

Code:

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

class SimpleAuth {
  public function createUser($username, $password) {
    $CI =& get_instance();
    $CI->load->library('database');
    
  }
}
?>

this code gives me the error while loading the database