title: How to subscribe to CustomBox Modal close event
body: <p>i have a modal implemented. I am currently using the FadeIn modal found here <a href="https://htmlstream.com/preview/unify-v2.5.1/unify-main/shortcodes/shortcode-base-modals.html" rel="nofollow noreferrer">https://htmlstream.com/preview/unify-v2.5.1/unify-main/shortcodes/shortcode-base-modals.html</a> From looking at the code it's utilizing CustomBox found here <a href="http://dixso.github.io/custombox/" rel="nofollow noreferrer">http://dixso.github.io/custombox/</a></p>
  
  <pre><code>&lt;a class="btn u-btn-primary" href="#modal1" data-modal-target="#modal1" data-modal-effect="fadein"&gt;Launch Modal
  &lt;/a&gt;
  
  &lt;!-- Demo modal window --&gt;
  &lt;div id="modal1" class="text-left g-max-width-600 g-bg-white g-overflow-y-auto g-pa-20" style="display: none;"&gt;
    &lt;button type="button" class="close" onclick="Custombox.modal.close();"&gt;
      &lt;i class="hs-icon hs-icon-close"&gt;&lt;/i&gt;
    &lt;/button&gt;
    &lt;h4 class="g-mb-20"&gt;Modal title&lt;/h4&gt;
    &lt;p&gt;Modal Body&lt;/p&gt;
  &lt;/div&gt;
  &lt;!-- End Demo modal window --&gt;
  </code></pre>
  
  <p>I can see that CustomBox has the event type Closed but i'm not sure how to properly subscribe to that event. I've added the following code but nothing happens. After the modal is closed.</p>
  
  <pre><code>document.addEventListener('custombox.close', function() {
  
  });
  </code></pre>
  
  <p>May I ask how do i properly subscribe to CustomBox's close event? </p>