title: 500 error on function call in Codeigniter
body: <p>I am using just installed CI 2.1.3
  Following phpacademy tutorial I wrote in the routes.php:</p>
  
  <pre><code>$route['default_controller'] = "site"; 
  </code></pre>
  
  <p>(instead of: $route['default_controller'] = "welcome";)</p>
  
  <p>and in controllers/site.php:</p>
  
  <pre><code>&lt;?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
  class Site extends CI_Controller {
        public function index() {
          echo "default function started.&lt;br/&gt;";
  
        }
        public function hello(){
          echo "hello function started.&lt;br/&gt;";
        }
  }
  </code></pre>
  
  <p>After uploading it to the server and going to the [www.mydomain.ext] it works ok (writes: "default function started.") BUT if I add 'this->hello();' to the index() function it throws a 500 error.</p>
  
  <p>Why does it happen and how can I resolve this?</p>
  
  <p>Thank you in advance.</p>