WPF Desktop app with MVVM, Booking form

App has been fully refactored to use MVVM pattern.

The Manage Users screen has been reworked so the list and form are on the same screen.

The Make Booking screen has all the controls data-bound to the View Model. What's missing is showing the assets for the selected room, more sensible defaults for date/time fields, and validation.

There is now a global application exception handler for unhandled exceptions, which shows a error message box that quits the app after pressing OK.

Both screens above still do not have proper validation and exception handling implemented yet.

The password field bug which Brett found should be fixed now.