title: WPF Open a Modal window from UserControl
body: <p>I have a MainWindow in my WPF app.</p>
  
  <p>This MainWindow has a menu on the left and when a menu option is selected a UserControl is loaded on the right.
  This is similar to Master Pages in asp.net</p>
  
  <p>What I want to do now is to have a modal window show from the UserControl which will only allow the user to interact with the modal window.</p>
  
  <p>I have seen examples of the Main Window showing a modal window (<a href="http://www.codeproject.com/Articles/36516/WPF-Modal-Dialog" rel="nofollow noreferrer">http://www.codeproject.com/Articles/36516/WPF-Modal-Dialog</a>) but not sure on how to load this from a UserControl.</p>