I am a student and am building a C# WPF application. It has three windows:

1. Sign in window
2. Create account window
3. and Main application window.

I uploaded a figure to show the type of navigation I am trying to implement: 

![http://picturepush.com/public/8870554](https://i.stack.imgur.com/1ga2W.png)

I do not think it is correct to make a window show up/hide inside the close/load event of another window.

1. Can someone show me the right way to implement this navigation?
2. Also, is it a good practice to make the three windows private properties of the application class?
3. The last window has a frame control to support page navigation. Again, is it better to make the three pages private properties of MainWindow application?

I am sorry if this is so obvious or easy to do.
Thanks