title: WPF bind IsEnabled on other controls if a listbox has a select item
body: <p>I have a grid with 2 columns, a listbox in column 0 and a number of other controls in the a secondary grid in the main grids column 1.</p>
  
  <p>I want this controls only to be enabled (or perhaps visible) if an items is selected in the listbox through binding.  I tried on a combo box:</p>
  
  <pre><code>IsEnabled="{Binding myList.SelectedIndex}"
  </code></pre>
  
  <p>But that does not seem to work.</p>
  
  <p>Am I missing something?  Should something like this work?</p>
  
  <p>thanks</p>