private void Calculate() { if (Birthdate.CalculateAge(BDate) > 135) { MessageBox.Show("Error! You are too old!"); } else if (BDate.CompareTo(DateTime.Today) > 0) { MessageBox.Show("Error! You don't exist yet!"); } else if (BDate.Month.CompareTo(DateTime.Today.Month) == 0 && BDate.Day.CompareTo(DateTime.Today.Day) == 0) { MessageBox.Show("Happy Birthday! Enjoy your special day!"); _bDate.CalculateAge(); _bDate.Westerngoroscope(); _bDate.Chinesegoroscope(); OnPropertyChanged("Age"); OnPropertyChanged("WGoroscope"); OnPropertyChanged("CGoroscope"); } else { _bDate.CalculateAge(); _bDate.Westerngoroscope(); _bDate.Chinesegoroscope(); OnPropertyChanged("Age"); OnPropertyChanged("WGoroscope"); OnPropertyChanged("CGoroscope"); } Thread.Sleep(1000); }