title: How to add another controller file in CI (codeigniter)
body: <p>the title seems stupid. but i met the problem,
  now i can just type <a href="http://ci.tao2tw.com" rel="nofollow noreferrer">http://ci.tao2tw.com</a>, then routes to my index.php/entry function
  but when i type <a href="http://ci.tao2tw.com/order" rel="nofollow noreferrer">http://ci.tao2tw.com/order</a> , i wanna routes to another controller 
  order.php , however it doesn't work !
  is anything wrong in my setting??</p>
  
  <p>now , i can not run test function under order controller by  <a href="http://ci.tao2tw.com/order/test" rel="nofollow noreferrer">http://ci.tao2tw.com/order/test</a> . instead, i should type
  htpp://ci.tao2tw.com/<strong>index.php</strong>/order/test
  i can not figure out?? </p>
  
  <p>thank you all in advance~
  <img src="https://i.stack.imgur.com/eWzNA.jpg" alt="enter image description here">
  <img src="https://i.stack.imgur.com/ua0WQ.jpg" alt="enter image description here">
  <img src="https://i.stack.imgur.com/i7saR.jpg" alt=""></p>
  
  <p>in routes.php</p>
  
  <pre><code>$route['default_controller'] = "index/entry";
  $route['order'] = "order"; 
  $route['404_override'] = '';
  </code></pre>
  
  <p>in config.php</p>
  
  <pre><code>$config['base_url'] = 'http://ci.tao2tw.com/';
  $config['index_page'] = '';
  </code></pre>
  
  <p>in controller/index.php (it works fine )</p>
  
  <pre><code>class Index extends CI_Controller {
  
      public function __construct() // to remember use public
      {
          parent::__construct(); 
          $this-&gt;load-&gt;helper('url');
          //anchor(); 
      }
      public function entry() //just show index
      {
          $this-&gt;load-&gt;view('index_view',$data);      
  
      }
  
  }
  </code></pre>
  
  <p>in controller/order.php ( no work  )</p>
  
  <pre><code>&lt;?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
  
  class Order extends CI_Controller {
  
      public function __construct() // to remember use public
      {
          parent::__construct(); 
          $this-&gt;load-&gt;helper('url');
  
      }
      public function fill($action) // 顯示填寫表單
      {
          echo "test";
      }
     //http://codeigniter.com/user_guide/libraries/uri.html
      public function order($action)
      {
          echo $action;
      }
  }
  
  ?&gt;
  </code></pre>
  
  <p>.htaccess file</p>
  
  <pre><code>RewriteEngine on
  RewriteCond $1 !^(index\.php|css|flash|images|img|includes|js|language|robots\.txt)
  RewriteRule ^(.*)$ index.php/$1 [L]
  ~
  </code></pre>