title: Fatal error: Class not found in codeigniter
body: <p>I have created a model <code>Admin_Model</code> under <code>Application\core</code> directory of code igniter. I put all basic database operations under it. When I try to extend my models who are under <code>Application\model</code> directory, it throws error.</p>
  
  <p><code>Fatal error: Class 'Admin_Model' not found in &lt;path to root&gt;/application/models/new_model.php on line 3</code></p>
  
  <p>Should I miss any configuration?</p>