Paste code

class Form extends CI_Controller {

    public function index()
    {
            $this->load->helper(array('form', 'url'));

            $this->load->library('form_validation');

$this->form_validation->set_rules('username', 'Username', 'trim|required|min_length[5]|max_length[12]');
$this->form_validation->set_rules('password', 'Password', 'trim|required|min_length[8]');
$this->form_validation->set_rules('passconf', 'Password Confirmation', 'trim|required|matches[password]');
$this->form_validation->set_rules('email', 'Email', 'trim|required|valid_email');

            if ($this->form_validation->run() == FALSE)
            {
                    $this->load->view('welcome');
            }
            else
            {
                    $this->load->view('formsuccess');
            }
    }

}