multilanguage codeigniter ERROR - 2013-02-02 13:20:09 --> Could not find the language line "login"

[eluser]dinisptc[/eluser]
multilanguage codeigniter

/application/language/french/
user_lang.php

i have a language file in french

$lang['login_login'] = 'Connecté';

/application/language/french/
user_lang.php

i have a language file in english

$lang['login_login'] = 'Login';


at the user controller
at the constructor i loaded the following

$this->load->helper('url');

$this->load->helper('language');

in the function index i have loaded the file

public function index()
{

$this->lang->load('user_lang', 'french');
}


at the view user

<div class="pageTitle">&lt;?=$this->lang->line('login');?&gt;</div>

at the log i have this error :
ERROR - 2013-02-02 13:20:09 --&gt; Could not find the language line "login"


how can i change from one language to another with a link ?