title: Trigger event with parameters
body: <p>This is pretty annoying. I want to just trigger an event in javascript. I need to pass the event object into the parameters as usual and an additional custom parameter.</p>
  
  <p>In jQuery, this would be super easy:</p>
  
  <pre><code>$('#element').trigger('myevent', 'my_custom_parameter');
  </code></pre>
  
  <p>But I don't want to use this however. Every other question I have found relating to this has just suggested 'use jQuery!' It's for a plugin I'm developing and to require jQuery for one method is pretty silly. Can anyone point to a way to do the above in vanilla JS that's cross-browser compatible?</p>