How do I retrieve a uri segment in a hook?

[eluser]Salvatore Formisano[/eluser]
Heh.. it gets even funnier

Code:

<?
function pick_language() {

  require_once(APPPATH.'/config/language.php');

  session_start();

  $libs = is_loaded();
  $x=$libs['uri']->segment(1); // keys in this one are always lowercase
  define('CURRENT_LANGUAGE', $x);
}

?>

returns

Code:

Fatal error: Call to undefined function is_loaded() in /Users/rino/Sites/gerardopanariello/application/hooks/pick_language.php on line 63