private void cmbSeqHeading_PreviewKeyDown(object sender, KeyEventArgs e) { if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control && e.Key == Key.Insert) { tsmvm.InsertNewSubHeading(); e.Handled = true; txtBotNote.Text = ""; txtTopNote.Text = ""; } else if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control && e.Key == Key.Delete) { tsmvm.DeleteNewSubHeading(); e.Handled = true; } }