public static void Show()
        {
            var vm = new TicketPurchaseViewModel();
            var v  = new TicketPurchaseView();

            v.DataContext  = vm;
            vm.CloseWindow = v.Close;

            v.Show();
        }
 private void ticketPurchaseHandler(object param)
 {
     TicketPurchaseViewModel.Show();
 }