title: Adding new node to existing XmlDocument object
body: <p>I have an xml of following format.</p>
  
  <pre><code>&lt;BOOKS&gt;
      &lt;BOOK&gt;
          &lt;TITLE&gt;book 1&lt;/TITLE&gt;
          &lt;AUTHOR&gt;author 1&lt;/AUTHOR&gt;       
          &lt;PRICE&gt;10.90&lt;/PRICE&gt;
          &lt;YEAR&gt;1985&lt;/YEAR&gt;
      &lt;/BOOK&gt;
      &lt;BOOK&gt;
          &lt;TITLE&gt;book 2&lt;/TITLE&gt;
          &lt;AUTHOR&gt;author 2&lt;/AUTHOR&gt;       
          &lt;PRICE&gt;20.90&lt;/PRICE&gt;
          &lt;YEAR&gt;1995&lt;/YEAR&gt;
      &lt;/BOOK&gt;
  &lt;/BOOKS&gt;
  </code></pre>
  
  <p>I have an <code>Add(XmlDocument xDoc, Book newBook)</code> method to add new book to the <code>XmlDocument</code> object that is passed to the <code>Add(..)</code> method. How can I do this. </p>