Can't set customer form error

Hello,

I want to set a customer error message.  Can anyone tell me why this doesn't it appear?

Thanks,

James

PHP Code:

        $this->form_validation->set_rules('username', 'Username', 'trim|required|xss_clean');
        $this->form_validation->set_rules('password', 'Password', 'trim|required|xss_clean');


        if ($this->form_validation->run() == FALSE) {

            $this->load->view('register/header');
            $this->load->view('register/researcher_form');
            $this->load->view('footer');

        } else {

            $username = $this->input->post('username', TRUE);
            $password = $this->input->post('password', TRUE);

            // Check the username and password
            $researcher_id = $this->user->researcher_login($username, $password);

            if ($researcher_id == TRUE){

                redirect("/register/study/");

            } else {

                $this->form_validation->set_message('login failed', 'Your username and password may be wrong.');
                
                $this->load->view('register/header');
                $this->load->view('register/researcher_form');
                $this->load->view('footer');

            }

        }

    }