cannot send hidden fields to the controller

[eluser]dinisptc[/eluser]
solved this issue

Code:

<?php echo validation_errors();

$today =date("Y-m-d");
$hidden = array('data_criacao' => $today, 'identidade' => $this->session->userdata('user_id'));

?>
<?php echo form_open('empregos/inserir','', $hidden); ?>

thanks
Obrigado
Pedro