title: Scroll back to the top of scrollable div
body: <pre class="lang-html prettyprint-override"><code>&lt;div id="containerDiv"&gt;&lt;/div&gt;
  </code></pre>
  
  <pre class="lang-css prettyprint-override"><code>#containerDiv {
    position: absolute;
    top: 0px;
    width: 400px;
    height: 100%;
    padding: 5px;
    font-size: .875em;
    overflow-y: scroll;
  }
  </code></pre>
  
  <pre class="lang-js prettyprint-override"><code>document.getElementById("containerDiv").innerHTML = variableLongText;
  </code></pre>
  
  <p>How to reset the scroll position back to top of container div the next time?</p>