title: Replace last 5 character from username with x
body: <p>I have to hide the last 5 characters of the username .
  Below is the code </p>
  
  <pre><code>&lt;ul&gt;
  &lt;li&gt;
              &lt;/dl&gt;
                  &lt;dl&gt;
                  &lt;dt&gt;Username:&lt;/dt&gt;
                  &lt;dd id="up-d-username"&gt;AZRT435231
                  &lt;/dd&gt;
              &lt;/dl&gt;
  &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>I need to replace the last 5 characters with a "X" so the output should be AZRT4XXXXX . Also is it possible that the user do not see this name from the source of the page using tools like firebug?</p>