problem with language & validation config

[eluser]taschentuch[/eluser]
hi guys have a little problem :/

im using a form_validation.php config

Code:

$config = array(
                 'adduser' => array(
                                    array(
                                            'field' => 'username',
                                            'label' => $this->lang->line('username'),
                                            'rules' => 'required|
                            min_length['.$this->config->item('username_min_length', 'tank_auth').']|
                            max_length['.$this->config->item('username_max_length', 'tank_auth').']|
                            usernamecheck'
                                         ),
                                    array(
                                            'field' => 'password',
                                            'label' => $this->lang->line('password'),
                                            'rules' => 'required|
                            min_length['.$this->config->item('password_min_length', 'tank_auth').']|
                            max_length['.$this->config->item('password_max_length', 'tank_auth').']|
                            xss_clean|
                            alpha_dash'
                                         ),
                                    array(
                                            'field' => 'email',
                                            'label' => $this->lang->line('email'),
                                            'rules' => 'required|
                            valid_email|
                            emailcheck'
                                         )
                                    )                        
               );

but got a error:

A PHP Error was encountered
Severity: Notice
Message: Undefined property: CI_Loader::$lang
Filename: config/form_validation.php
Line Number: 7
Fatal error: Call to a member function line() on a non-object in /var/www/system/application/config/form_validation.php on line 7

how can i feetch language in /config/form_validation.php ?

thx

[eluser]Isern Palaus[/eluser]
Use:

Code:

'label' => 'lang:email',