title: How to open pop-up from link button and close it using button inside the pop-up?
body: <p>I have main window, containing grid with different user controls. Each control is defined in separate Xaml. Then in MainWindow.xaml i match all particles of my main window.</p>
  
  <p>One of my userControls is a menu, containing buttons. 
  i want to call popup after clicking some button in menu. Popup will contain some text, buttons and will overlay the main window.
  So the question is how to call pop-up from menu-button and close it from button located on pop-up?</p>
  
  <p>Thanks!</p>