An application sends a DM_GETDEFID message to get the ID of the default push-button control for a dialog box.
wParam
This parameter is not used.
lParam
This parameter is not used.
The return value is a 32-bit value. If the default push-button has an ID value, the high-order word contains DC_HASDEFID and the low-order word contains the ID value. If the default push-button does not have an ID value, the return value is zero.
DM_SETDEFID