title: Setting Label object as per Listbox selected item
body: <p>I need to bind a <code>Label</code> to two <code>ListBox</code>es. In order to do this I have set the <code>SelectionChanged</code> property of both <code>ListBox</code>es to the same function:</p>
  
  <pre><code>&lt;ListBox Name="ListBox1" SelectionChanged="UpdateSelectedItem" /&gt;
  &lt;ListBox Name="ListBox2" SelectionChanged="UpdateSelectedItem" /&gt;
  &lt;Label Name="DetailsLabel" DataContent="DefinedElsewhere" /&gt;
  </code></pre>
  
  <p>However I am having trouble finding what the selected item actually is. I have gone through all the properties of the sending object and the SelectionChangedEventArgs but I cannot find it. The <code>ListBox</code> is bound to an <code>ObservableCollection</code> of objects, and I would like the <code>Label</code> to display the properties of the last selected item, no matter from which <code>ListBox</code> it was selected. How do I find that?</p>
  
  <pre><code>private void UpdateSelectedItem(object sender, SelectionChangedEventArgs e)
  {
       DetailsLabel.Content = ???;
  }
  </code></pre>