title: WPF: Best way to raise a popup window that is modal to the page?
body: <p>I am building a WPF app using navigation style pages and not windows. 
  I want to show a window inside a page, this window must be modal to the page, but allow the user to go to other page, and go back to the same page with the modal window in the same state.</p>
  
  <p>I have tried with the WPF popup control but the problem is that the control hides everytime you navigate away from the page. I guess that I can write the code to show it again, but does not seams the right way.</p>
  
  <p>What is the best way to do this in WPF?</p>