>>>>You should pass an object to form B:
>>>>

>>>>oCallobject=createobject('custom')
>>>>oCallobject.addproperty('returnvalue')
>>>>=createobject('formb',oCallobject)
>>>>....
>>>>

>>>>and you will accept oCallobject in FormB.Init event, and populate Returnvalue property within that form.
>>>>
>>>>
>>>
>>>Looks good.
>>>
>>>How do I trigger FormA to know that FormB is now gone and I have a change in ReturnValue property (so as to update an input grid with that value and refresh the form)?
>>>
>>>Thanks!
>>>
>>Is FormB modal or modeless?
>
>FormA is MODAL and FormB is MODELESS.

You cannot call modeless form from modal. It may create interface confusion. Maybe you meant the opposite: modal form is called from the modeless?