Menu Messages

I want to capture a screen after a menu item is selected AND after the dropdown menu has disappeared from the screen, and prior to the dialog box popping up as a result of the menu item.
Does anyone know the wm_command I should be looking for.

If I choose WM_SYSCOMMANDS is there then a lParam or a wParam value I should look for so I can pick up the screen prior to the drop down occuring. If I choose WM_SYSCOMMANDS all the time it slows the program down too much

Please email me at ds@infra.com.au

Thank you

David Stephen