How can I use a Push Button callback function to call Radio Button Group's SelectionChangeFcn?

My codes are wrong. How can I make it work by modifying below codes?

function pushbutton1_Callback(hObject, eventdata, handles)

% Add & Save into the system

% hObject handle to pushbutton3 (see GCBO)

% eventdata reserved - to be defined in a futurer version of MATLAB

% handles structure with handles and user data (see GUIDATA)

switch get(get(uipanel1_SelectionChangeFcn,'SelectedObject'),'Tag')

    case 'RadioButton 1',  Output = 'A';

    case 'RadioButton 2',  Output = 'B';

    case 'RadioButton 3',  Output = 'C';

    case 'RadioButton 4',  Output = 'D';

    otherwise, Output = '';
end

Answer 1

[Zheng]

just change uipanel1_SelectionChangeFcn to handles.uipanel1