If this is a subclass of a class that actually has the Destroy method code, you either need to remove the PROC DESTROY/ENDPROC from Pump.prg or put a DODEFAULT() in it. If Pump.prg just has:

PROCEDURE DESTROY

ENDPROC

with nothing in between, the code in the parent class does not fire. So, put a DODEFAULT() in it or remove those 2 lines.

>I create a comm object and event handler in form init()
>
>When the form is closed by clicking upper right corner, event handler Destroy()
>event does not fire. Why ?
>
>

>* Form Init()
>this.oComm = createobject( "mscommlib.MSComm" )
>EVENTHANDLER( this.oComm, NEWOBJECT("commevents", 'pump.prg' ) )
>

>
>
>* File pump.prg contains:
>

>DEFINE CLASS commevents AS custom
>IMPLEMENTS DMSCommEvents IN "mscommlib.MSComm"
>
>procedure Destroy
>* this event does not fire when form is closed. why ?
>ENDPROC
>
>PROCEDURE DMSCommEvents_OnComm() AS VOID;
>HELPSTRING "Occurs whenever the value of the CommEvent property changes."
>ENDPROC
>ENDDEFINE
>