CodeIgniter ошибка $dx_auth

После добавления строк:

public function create() {

if(!$this->dx_auth->is_admin()) {
show_404();
}

Получаю ошибку на http://kinomonster.com:8080/news/create :

A PHP Error was encountered
Severity: Notice

Message: Undefined property: News::$dx_auth

Filename: controllers/News.php

Line Number: 38

Backtrace:

File: C:\xampp\htdocs\kinomonster\application\controllers\News.php
Line: 38
Function: _error_handler

File: C:\xampp\htdocs\kinomonster\index.php
Line: 315
Function: require_once
An uncaught Exception was encountered
Type: Error

Message: Call to a member function is_admin() on null

Filename: C:\xampp\htdocs\kinomonster\application\controllers\News.php

Line Number: 38

Backtrace:

File: C:\xampp\htdocs\kinomonster\index.php
Line: 315
Function: require_once

Что делать?

Перед этим в DX_Auth.php сделал так: 

//function DX_Auth()
function __construct()

Код контроллера  C:\xampp\htdocs\kinomonster\application\controllers\News.php :

<?php

defined('BASEPATH') OR exit('No direct script access allowed');


class News extends MY_Controller {
public function __construct() {
parent::__construct();
$this->load->model('news_model');
}

public function index() {
$this->data['title'] = "Все новости";
$this->data['news'] = $this->news_model->getNews();

$this->load->view('templates/header', $this->data);
$this->load->view('news/index', $this->data);
$this->load->view('templates/footer');
}

public function view($slug = NULL) {
$this->data['news_item'] = $this->news_model->getNews($slug);

if(empty($this->data['news_item'])) {
show_404();
}

$this->data['title'] = $this->data['news_item']['title'];
$this->data['content'] = $this->data['news_item']['text'];

$this->load->view('templates/header', $this->data);
$this->load->view('news/view', $this->data);
$this->load->view('templates/footer');
}

public function create() {

if(!$this->dx_auth->is_admin()) {
show_404();
//$this->load->helper('url_helper');
//redirect('/', 'location');
}

$this->data['title'] = "Добавить новость";

if($this->input->post('slug') && $this->input->post('title') && $this->input->post('text')) {

$slug = $this->input->post('slug');
$title = $this->input->post('title');
$text = $this->input->post('text');

if ($this->news_model->setNews($slug, $title, $text)) {
$this->load->view('templates/header', $this->data);
$this->load->view('news/success', $this->data);
$this->load->view('templates/footer');}
}
else {
$this->load->view('templates/header', $this->data);
$this->load->view('news/create', $this->data);
$this->load->view('templates/footer');
}
}

public function edit($slug = NULL) {
$this->data['title'] = "редактировать новость";
$this->data['news_item'] = $this->news_model->getNews($slug);

$this->data ['title_news'] = $this->data['news_item']['title'];
$this->data ['content_news'] = $this->data['news_item']['text'];
$this->data ['slug_news'] = $this->data['news_item']['slug'];
if($this->input->post('slug') && $this->input->post('title') && $this->input->post('text')) {
$slug = $this->input->post('slug');
$title = $this->input->post('title');
$text = $this->input->post('text');
if($this->news_model->updateNews($slug, $title, $text)){
echo "Новость успешно отредактирована";
}
}

$this->load->view('templates/header', $this->data);
$this->load->view('news/edit', $this->data);
$this->load->view('templates/footer');

}

public function delete($slug = NULL) {
$this->data['news_delete'] = $this->news_model->getNews($slug);
if(empty($this->data['news_delete'])) {
show_404();
}

$this->data['title'] = "удалить новость";
$this->data['result'] = "Ошибка удаления ".$this->data['news_delete']['title'];

if($this->news_model->deleteNews($slug)) {
$this->data['result'] = $this->data['news_delete']['title']." успешно удалена";
}
$this->load->view('templates/header', $this->data);
$this->load->view('news/delete', $this->data);
$this->load->view('templates/footer');

}

 

 

}