title: What is the effect of `return false;` on Custom Events?
body: <p><a href="https://stackoverflow.com/questions/10463218/jquery-custom-events-return-value">Similar to this question about jQuery custom events</a>, I'm trying to find out what the effect of <code>return false;</code> is, with the exception that I am not using jQuery. I'm triggering a custom event via the following method:</p>
  
  <pre><code>var event = document.createEvent('Event');
  event.initEvent('CustomName', false, true);
  element.dispatchEvent(event);
  </code></pre>
  
  <p>This is wrapped in a function, and I return the event object after dispatching the event. Now, I'm looking for a way in the triggering code to see if one of the listeners returned <code>false</code> so that I can prevent further execution. How would I be able to detect if one of the listeners returned <code>false</code> in a cross-browser manner (IE 7+)?</p>