title: Databinding in the same Control on 2 different DataContext
body: <p>In Silverlight I've a page with some controls and a listbox.</p>
  
  <p>I'm using MVVM and the dataContext of the listbox is defined like this. In my model I have a property ProductCommand and this ProductCommand object contains a list of product named Products.</p>
  
  <p>My listbox is in a grid with the datacontext defined as the ProductCommand property. and the databinding for the listbox is set to the Products (Binding="{Product, Mode=twoWay}").</p>
  
  <p>In my model class I also have a selectedProduct property, and I want to bound it to the SelectedItem property of the listbox.</p>
  
  <p>How can I do that?</p>