Hi!

I need to create one class (Dad) and within this class Dad I will have an other class (Son).
Inside of the class Son need have one reference of the Dad, or be, I have a Cycle Reference, only that with this I can't release theses class, they stay in memory.
Do you know any way to intercept when the class is going release to can remove the reference of class Dad in Son before?
Follow sample code:

DEFINE CLASS dad as Custom
	son = null
	PROCEDURE init()
		this.son = CREATEOBJECT([son])
		this.son.dad = this
	ENDPROC
	PROCEDURE destroy()
		MESSAGEBOX([Dad - Destroy])
	ENDPROC
ENDDEFINE
***--------------------------------***
DEFINE CLASS son as Custom
	dad = null
	PROCEDURE init()
	ENDPROC
	PROCEDURE destroy()
		MESSAGEBOX([Son - Destroy])
	ENDPROC
ENDDEFINE

To do a test:

1: Create one PRG (MyPrg, for sample)
2: In Command Window do:
   - Set Procedure To MyPrg
   - X = CREATEOBJECT([Dad])
   - Release X 
   - In this moment don't appear any message, but if you to comment the 
     line "this.filho.pai = this" the messages of the Destroy event appear.

P.S.: I trying to use the Destroy, Unload, QueryUnload events, but didn´t work. I'm using VFP8 and W2K Professional. Sorry my bad English!
Thanks!