title: Get element by id and change its sibling value
body: <p><strong>HTML</strong></p>
  
  <pre><code>&lt;table&gt;
      &lt;tr id="1"&gt;
          &lt;td id="a"&gt;aa&lt;/td&gt;
          &lt;td&gt;bb&lt;/td&gt;
      &lt;/tr&gt;
  &lt;/table&gt;
  </code></pre>
  
  <p><strong>JavaScript</strong></p>
  
  <pre><code>document.getElementById("1").children[1].innerHTML="newB"  // it works as expected.     
  document.getElementById("a").nextSibling.innerHTML="newB" // it does not work.
  </code></pre>
  
  <p>How can I change <code>td id="a"</code> sibling value using 2nd approach?</p>