title: be able to change disqus_identifier on some pages
body: <p>I'm using the wordpress plugin.</p>
  
  <p>I've found the code in the plugin file "comments.php" that defines the identifier for a page:</p>
  
  <pre><code>var disqus_identifier = '&lt;?php echo dsq_identifier_for_post($post); ?&gt;';
  </code></pre>
  
  <p>What I've come up with so far is to replace it with:</p>
  
  <pre><code>var disqus_identifier = '&lt;?php echo get_post_meta($post-&gt;ID, 'dis_ident_field', true); ?&gt;';
  </code></pre>
  
  <p>This means that it will get it's disqus_identifier from a custom field from Wordpress called dis_ident_field, but I'm worried about this method. For pages where I don't populate this field, I now have no identifier at all in the javascript in the page source. </p>
  
  <p>Can someone explain why having no id is bad, because the comments still work on all those pages properly, so it's getting an id from somewhere.</p>