private void btnModifyCustomer_Click(object sender, RoutedEventArgs e)
        {
            CustomerWindow win = new CustomerWindow(c, this);

            win.Show();



            this.Hide();
        }
        private void btnNext_Click(object sender, RoutedEventArgs e)
        {
            this.booking = new Booking();

            try
            {
                SelectedDatesCollection Dates = calendarBookingDate.SelectedDates;

                if (Dates.Count <= 1)
                {
                    throw new ArgumentException("You need to select and drag a range of dates!");
                }
                if (Dates.Count > 1)
                {
                    booking.ArrivalDate   = Dates[0];
                    booking.DepartureDate = Dates[Dates.Count - 1];
                }
                if (Dates[0].Date > Dates[Dates.Count - 1].Date)
                {
                    throw new ArgumentException("The Arrival Date Can't be after the Departure Date!");
                }
                if (customer != null)
                {
                    BookingDetails winB = new BookingDetails(booking, customer, true);
                    winB.Show();
                    this.Close();
                }
                else
                {
                    CustomerWindow win = new CustomerWindow(booking);
                    win.Show();
                    this.Close();
                }
            }
            catch (Exception ee)
            {
                MessageBox.Show(ee.Message, "Booking");
            }
        }