title: Checking if a XML child element exists with Linq to XML
body: <p>I'm trying to get my head around a problem I'm having in Linq to XML, seems like it should be pretty simple but even after browsing the Linq to XML questions here, I can't quite get it.</p>
  
  <p>Take something along the lines of the following XML:</p>
  
  <pre><code>&lt;users&gt;
      &lt;user id="1"&gt;
          &lt;contactDetails&gt;
              &lt;phone number="555 555 555" /&gt;
          &lt;/contactDetails&gt;
      &lt;/user&gt;
      &lt;user id="2"&gt;
          &lt;contactDetails /&gt;
      &lt;/user&gt;
  &lt;/users&gt;
  </code></pre>
  
  <p>I now want to check if user with id 2 has a phone number.</p>
  
  <p>Could someone suggest a solution, as I said seems, like it should be simple...</p>
  
  <p>Cheers,
  Ola</p>