title: Selected block only need to be fix at top while scrolling
body: <p>Keep only the selected <code>li</code>elements of the list  fixed to the top.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>jQuery(".list-outer ul li").click(function() {
    jQuery(this).toggleClass("li-active");
  });</code></pre>
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.li-active {
    background: red;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="list-outer"&gt;
    &lt;ul&gt;
      &lt;li&gt;
        Content blk1
      &lt;/li&gt;
      &lt;li&gt;
        Content blk2
      &lt;/li&gt;
      &lt;li&gt;
        Content blk3
      &lt;/li&gt;
      &lt;li&gt;
        Content blk4
      &lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p><strong>Example:</strong> If selected  second and fourth <code>li</code> elements, when scroll happens keep them fixed on top.</p>