private void Button_Click(object sender, RoutedEventArgs e)
        {
            var window = new PersonWindow(null);

            if (window.ShowDialog() ?? false)
            {
                UpdatePeople();
            }
        }
        private void todayPeople_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            var selectedPerson = PatientDataGrid.SelectedItem as Person;

            if (selectedPerson != null)
            {
                var window = new PersonWindow(selectedPerson);
                if (window.ShowDialog() ?? false)
                {
                    UpdatePeople();
                }
                PatientDataGrid.UnselectAll();
            }
        }