Custom button LButtonUp issue.

Hi,

Created one CustomButton class derived from CButton class.
In CustomButton class, implemented the
ON_WM_LBUTTONUP
ON_WM_LBUTTONDOWN
messages.

If user tap on this button and hold drag some where else and release
on the Combobox or radiobutton on the screen, then the CustomButton's
OnLButtonUp will not be called because the the "stylus" released on
some other control.
How to handle the "OnLButtonUp" of the CustomButton?
Is there any other events?

Thanks in advance.

Regards,