title: Is it possible to get reference to comment element/block by JavaScript?
body: <p>This sounds a little crazy, but I'm wondering whether possible to get reference to comment element so that I can dynamically replace it other content with JavaScript.</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div id="header"&gt;&lt;/div&gt;
  &lt;div id="content"&gt;&lt;/div&gt;
  &lt;!-- sidebar place holder: some id--&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>In above page, can I get reference to the comment block and replace it with some content in local storage? </p>
  
  <p>I know that I can have a div place holder. Just wondering whether it applies to comment block. 
  Thanks.</p>