flCancel (ULONG) - input

The value of this flag specifies whether this call cancels the area definition:

EA_DRAW

Draw the area. This flag is the default.
EA_CANCEL
Cancel the area definition. Otherwise, draw the area.
Note: When GreBeginArea is not called and EA_CANCEL is set, GreEndArea is valid but has no effect, thus allowing the handling routine to reset an area bracket to a known state when it has no knowledge of the actual current state.