title: silverlight: setting RowDetailsTemplate controls from RowDetailsVisibilityChanged
body: <p>Given a silverlight datagrid with RowDetailsVisibilityMode="VisibleWhenSelected", on clicking a row in the datagrid, how do you set or bind the controls in the RowDetailsVisibilityChanged() event?</p>
  
  <pre><code>        &lt;data:DataGrid.RowDetailsTemplate&gt;
              &lt;DataTemplate&gt;
                  &lt;StackPanel&gt;
                      &lt;TextBlock Text="a" x:Name="_txt" /&gt;
                      &lt;ListBox x:Name="_lst"&gt;&lt;/ListBox&gt;
                  &lt;/StackPanel&gt;
              &lt;/DataTemplate&gt;
          &lt;/data:DataGrid.RowDetailsTemplate&gt;
  </code></pre>