title: Query xml file by attribute in .net
body: <p>How could I query an xml file, like the one below, with C# .NET 2.0? I have the id value and need to get the thumbnail image related to that id.</p>
  
  <pre><code>&lt;root&gt;
      &lt;categories&gt;
          &lt;category title="decking"&gt;
              &lt;photos&gt;
                  &lt;photo id="1" smallphoto="/files/images/photogallery/thumbs/EarthwoodEvolutions1_thumb.jpg"  /&gt;
                  &lt;photo id="2" smallphoto="/files/images/photo-gallery/thumbs/XLM401_thumb.jpg"  /&gt;
              &lt;/photos&gt;
          &lt;/category&gt;
      &lt;/categories&gt;
  &lt;/root&gt;
  </code></pre>