FORM VIEW

print validation_errors();
$form_attributes = array('class'=>'frm_login','id'=>'frm_login_completo');
print form_open('user/entrar',$form_attributes);
print "<span>Entre com as suas informações!</span>";
print form_label('E-mail','email');
print form_input('email','');
print form_error('email');
print form_label('Senha','password');
print form_password('password','');
print form_error('password');
print form_checkbox('keepLogged','Lembrar de mim!');
//print $captcha;
print form_submit('sent','Entrar');
print "<span><a href=\"".base_url()."index.php/user/registrar\">Registrar</span>";
print "<span><a href=\"".base_url()."index.php/user/recuperar\">Esqueci a minha senha</a></span>";
print "<span><a href=\"".base_url()."index.php/user/facebook\">Login with Facebook</a></span>";
print form_close();

USER / ENTRAR IN CONTROLLER

public function entrar(){
        $this->template->write_view('sidebar','user/login_main');
        $this->load->model('user/user_model');
        $this->form_validation->set_rules('email','E-mail','required|min_lenght[5]|valid_email');
        $this->form_validation->set_rules('password','Password','required');#|min_lenght[6] add later
        $this->form_validation->set_error_delimiters('<div class="erro">','</div>');

        if($this->input->post('sent'))
        {
            if($this->session->userdata('attempt') == $this->attempt_captcha){
                //Captcha
                print "CAPTCHA";
            }
            if($this->session->userdata('attempt') >= $this->attempt_recover){
                redirect('user/recuperar', 'refresh');
            }
            if($this->form_validation->run()){

                $email = $this->input->post('email');
                $passwd = md5($this->input->post('passwd'));
                $isValid = $this->user_model->verify($email,$passwd);
                if($isValid) {
                    $name = $this->user_model->getName($email);
                    $uid  = $this->user_model->getUID($email);
                    $user_data = array(
                        'logged'   => '1',
                        'email'    => $email,
                        'uid'      => $uid,
                        'username' => $name);
                    $this->session->set_userdata($user_data);
                    redirect(base_url(), 'refresh');
                }
                else {
                        $this->session->set_userdata('attempt',$this->session->userdata('attempt')+1);
                     }
            }
        }
        $this->template->render();
    }