To clarify, you mean a button with the Cancel property set True.

>>It triggers QueryUnload() event. See also the ReleaseType property.
>Execute NODEFAULT to preven in it form closing.
>
>>>When using a form in VFP9, I want to capture the "mouse click" on the red "X" close button and do some testing before I allow the user to close the form.
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>Just a note here, the QueryUnload() event is only called via the "Red-X" button; if you have a "Cancel" commandbutton that will close the form via a RELEASE thisform or thisform.Release() in the Click event, the QueryUnload event will not be called. You have to process the test in the commandbutton click event as well.