title: How to track custom JavaScript event in Google Tag Manager?
body: <p>I have a custom JS event that fires when accordion panel is opened. I would like to track the opening as Google Analytics event with panel id as the event label.</p>
  
  <p>Using the old non-GTM approach I would do it like this:</p>
  
  <pre><code>$('#my-accordion').on('down.zf.accordion', function(e, panel) {
    ga('send', 'event', 'accordion', 'open', panel.attr('id'));
  });
  </code></pre>
  
  <p>But I would like to do this with Google Tag Manager and with as less changes in the code on page as possible.</p>
  
  <p>So far I have created this in Google Tag Manager:</p>
  
  <p><strong>Trigger</strong>, type Custom Event that fires on 'down.zf.accordion'</p>
  
  <p><strong>Tag</strong>, type Universal Analytics with my tracking id, track type: Event (accordion, open, [probably a global JS variable that is set to panel.attr('id')?])</p>
  
  <p>But the tag won't even fire when testing in the GTM preview. What am I doing wrong?</p>