Get flags

        Entry:
          AH = 12h
          BH = 16h
          BL = object
               00h DWORD on top of stack
                   Mailbox, keyboard, or pointer only
               02h mailbox for task whose handle is on top of stack
               03h mailbox for current task
               04h keyboard for task whose handle is on top of stack
               05h keyboard for current task

        Return:
          STACK: DWORD current control flags

        Note:   This call is only available if the API level has been set
                to at least 2.2