title: How can the children listen/capture to the parent's event
body: <p>How can the parent fire the custom event to notify its children/siblings?
  For example:</p>
  <pre><code>&lt;div id=&quot;div1&quot;&gt;
     &lt;div id=&quot;div2&quot;&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  <p><code>div2</code> had <code>addEventListener('customEvent2', doSth)</code>, and then <code>div1</code> will fire a custom event (<code>customEvnet2</code>), but this will never trigger div2's <code>doSth</code> function.</p>
  <p>Sample code:  <a href="http://jsfiddle.net/r4tcT/2/" rel="nofollow noreferrer">http://jsfiddle.net/r4tcT/2/</a></p>
  <p>The &quot;div 1 trigger customEvent 2&quot; button never works</p>
  <p>so when a parent fire a custom event (dispatchEvent[IE9]/fireEvent[IE9-]/trigger[jQuery]), the children can not capture the event.</p>
  <p>Is there any workaround?</p>