user.php

<?php

class user extends CI_Controller {

    public function __construct() {
        parent::__construct();
    }

    function login() {
        $data = '';
        if ($this->input->post('username')) {

            $this->load->model('bm_users');
            $user = $this->bm_users->login($this->input->post());
            if ($user !== 'failed') {
                $data['resp'] = '1';
            } else {
                $data['resp'] = '0';
                $data['err'] = 'The username/password combination did not match. Please try again.';
            }

            $dta = json_encode($data);
            echo $dta;
        } else {
            $this->load->view('login');
        }

    }

    function login_check() {
        vardump($_POST);
    }

}