title: Show footer when user scrolls to the bottom of the page
body: <p>Here is my footer code.</p>
  
  <pre><code>&lt;div class="row"&gt;
      &lt;div class="col-md-12"&gt;
          &lt;div&gt; the part that always showing at the bottom  &lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="col-md-12"&gt;
          &lt;div&gt; show only if the user reaching the bottom of the page &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>My problem is I want my footer stick to the bottom of the page until the user reach the bottom, then show the other content. </p>