title: Create xml format c#
body: <p>I want to make xml format like this in c#</p>
  
  <pre><code>&lt;?xml version='1.0' encoding='us-ascii'?&gt; 
  &lt;root&gt;
  &lt;key value="22.wav"&gt;
  &lt;Index&gt;1&lt;/Index&gt;
  &lt;Index&gt;20&lt;/Index&gt;
  &lt;Index&gt;21&lt;/Index&gt;
  &lt;/key&gt;
  &lt;key value="EFG.wav"&gt;
  &lt;Index&gt;5&lt;/Index&gt;
  &lt;Index&gt;22&lt;/Index&gt;
  &lt;/key&gt;
  &lt;/root&gt;
  </code></pre>
  
  <p>How do i form like this please help me</p>