title: Durandal Modals and navigation (i.e. back button)
body: <p>This issue is easily seen in the durandal sample application:</p>
  
  <p>1) Navigate to "Modal Dialogs" demo
  2) Click the button to show the modal
  3) Click the browser back button</p>
  
  <p>When doing this, the page navigates to the previous screen while keeping the dialog open, which is almost never what you want.  </p>
  
  <p>Is there a best practice here for either closing dialogs or preventing navigation if one is open?</p>