Using pop-up menu to enable/disable a button group

I have 2 button groups and a pop-up menu to switch from one button group to another. I try using this code but it didn't work for me. What can I do?

switch get(hObject, 'Value')
    case 1
        set (handles.panel_LG, 'Visible', 'on')
        set (handles.panel_Newton, 'Visible', 'off')
    case 2
        set (handles.panel_LG, 'Visible', 'off')
        set (handles.panel_Newton, 'Visible', 'on')
end

[Jan]

Please mention, what "didn't work" means. Do you get an error message or does the result differ from your expectations? Where is this code stored? What is hObject? What is the value of hObject.Value?

I have removed a duplicate question posted at the same time.