void OnSaveButtonClicked(object sender, EventArgs args)
 {
     Note note = new Note
     {
         Title = entry.Text,
         Text = editor.Text
     };
     note.Save(FILENAME);
     loadButton.IsEnabled = true;
 }
 void OnLoadButtonClicked(object sender, EventArgs args)
 {
     Note note = new Note();
     note.Load(FILENAME);
     entry.Text = note.Title;
     editor.Text = note.Text;
 }