I have a nav button class which had some references to THISFORM.DataEnvironment. Of course, it was hosed when I dropped it into a form that was in a formset. So, I gave the navclass a property "oFormOrSet", and in a navclass method called from the .Init, I put this:

* Figure out if it's a form or a formset,
* set everything accordingly

IF TYPE("THISFORMSET") = "O"
	THIS.oFormOrSet = THISFORMSET
ELSE
	THIS.oFormOrSet = THISFORM
ENDIF

I used it to say things like .oFormOrSet.DataEnvironment. But when I needed it in the navclass.Destroy to clean up things in the DE, my reference was gone, even though THISFORMSET or THISFORM still existed. So I had to do something similar in the navclass.Destroy with a local variable:

* the object reference THIS.oFormOrSet
* seems to have been detroyed, even though
* the form or formset still exists
IF TYPE("THISFORMSET") = "O"
	oFormThis = THISFORMSET
ELSE
	oFormThis = THISFORM
ENDIF

and then used it to say oFormThis.DataEnvironment. Is it really supposed to be this way?