private void dayOfaWeekBox_Click(object sender, EventArgs e) { if (this.morningAppointments + this.afternoonAppointments == 0) { FeedbackWindow message = new FeedbackWindow(); message.setMessageForNoAppointmentsPerDay(); message.Show(); return; } if (this.date.Date < DateTime.Today.Date) { FeedbackWindow message = new FeedbackWindow(); message.setMessageForBookingNotAvailableForDateDueToDateInThePast(); message.Show(); return; } this.singleDay.ShowDialog(); }