Codeigniter view within a view
For your controller, a method like this would be best to call all your variables:

$data = array(
    "add_user" =&gt; $this-&gt;load-&gt;view('form_add_user'),
    "username" =&gt; $username,
    "admin"    =&gt; $admin
);


(Variables are made up just for example)

Then, within your code, do this:

&lt;div class="tab-pane" id="tab_1_2"&gt;
    &lt;div class="portlet "&gt;
        &lt;div class="portlet-title"&gt;
            &lt;div class="caption"&gt;
                &lt;i class="icon-reorder"&gt;&lt;/i&gt; Nuevo Usuario
            &lt;/div&gt;
        &lt;/div&gt;
        &lt;?=$add_user;?&gt; &lt;!-- looks cleaner --&gt;
     &lt;/div&gt;
&lt;/div&gt;