title: Site_url not working in the navbar codeigniter 3
body: <p>I don't know why but the site_url is not working on the href of the nav bar. when I'm on the customers view page and selecting technicians tab, It doesn't jump on the technician's page and vice versa.
   I'm thinking that it has to do with the previous code. before, the one on the href was calling for an id. but I already checked all the css and javascripts/jquery codes connected to it and disabled it if ever but it's still not working. </p>
  
  <p>header.php</p>
  
  <pre><code>    &lt;ul role="tablist" class="nav nav-tabs nav-tabs-horizontal"&gt;
                &lt;li role="presentation"&gt;&lt;a href="&lt;?= site_url('customers');?&gt;" id="customers" aria-controls="customers" role="tab" data-toggle="tab"&gt;Customers&lt;/a&gt;&lt;/li&gt;
                &lt;li role="presentation"&gt;&lt;a href="&lt;?= site_url('technicians');?&gt;" id="technicians" aria-controls="technicians" role="tab" data-toggle="tab"&gt;Technicians&lt;/a&gt;&lt;/li&gt;
                &lt;li role="presentation"&gt;&lt;a href="#cs-users"  aria-controls="cs-users" role="tab" data-toggle="tab"&gt;Users&lt;/a&gt;&lt;/li&gt;
                &lt;li role="presentation"&gt;&lt;a href="#service-card" aria-controls="service-card" role="tab" data-toggle="tab"&gt;Service Card&lt;/a&gt;&lt;/li&gt;
                &lt;li role="presentation"&gt;&lt;a href="#rtv-card"  aria-controls="rtv-card" role="tab" data-toggle="tab"&gt;RTV Card&lt;/a&gt;&lt;/li&gt;
  
      &lt;/ul&gt;
  </code></pre>
  
  <p>I already omitted all the unnecessary id and classes. all tabs have their own views and controllers. this header is included in the controller of every tab pages. like this.</p>
  
  <p>customers.php</p>
  
  <pre><code>&lt;?php
  defined('BASEPATH') OR exit('No direct script access allowed');
  
  class Customers extends CI_Controller {
  
      public function __construct() {
  
          parent::__construct();
          $this-&gt;load-&gt;helper('url');
          $this-&gt;load-&gt;helper('form');
          $this-&gt;load-&gt;library('form_validation');
      }
  
      public function index() {
          $this-&gt;load-&gt;view('header');
          $this-&gt;load-&gt;view('customers');
      } 
  }
  
  ?&gt;
  </code></pre>
  
  <p>the url is already declared in the <code>autoload.php</code> but it's still not working.
  I tried using site_url on one of the home buttons and it is working. what do you think is wrong? I can't move on with this code and it troubles me for 2 days already. I hope someone help me. thanks!</p>