private void AddChore_OnClick(object sender, RoutedEventArgs e)
        {
            ScheduledChore temp = _main.SelectedChore;

            try
            {
                _main.AddingChore   = true;
                _main.SelectedChore = null;

                EditChoreDialog dlg = new EditChoreDialog {
                    DataContext = _main
                };
                dlg.ShowDialog();

                if (dlg.DialogResult == true)
                {
                    _main.AddChore();
                }
            }
            finally
            {
                _main.AddingChore   = false;
                _main.SelectedChore = temp;
            }
        }