class="alert alert-info">
      <strong>Heads up!</strong>
      You must manage the position of a pinned element and the behavior of its immediate parent. Position is controlled by <code>affix</code>, <code>affix-top</code>, and <code>affix-bottom</code>. Remember to check for a potentially collapsed parent when the affix kicks in as it's removing content from the normal flow of the page.
   </div>

   <h3>Via JavaScript</h3>
   <p>Call the affix plugin via JavaScript:</p>
   <pre class="prettyprint linenu