>>Hi,
>> I have a top level form and multiple MDI form. I place toolbar on my top level form and issue _SCREEN.ACTIVEFORM.mymethod(). It works most of the time, but VFP give error ACTIVEFORM is not an Object sometime... why does it happen? hor to solve?
>>
>>Thank you
>
>Sometimes, there is no ActiveForm at that time. It's safer to look for the form you really need, and use its reference to call the method, e.g.
>

>For Each oForm in _SCREEN.Forms
> If oForm.Name=="MyForm"
>  oForm.mymethod()
>  Exit
> Endif
>Endfor
>

Another thing which worked fine in 5.0 but behaves differently in 6, is that sometimes the _screen.activeform will not return a referrence to the active form, but to an ActiveX sitting on that form. One solution is to do something like this:

Function ActiveForm
oForm=_screen.ActiveForm
if not isnull(oForm)     && or should we check for type('oForm')='O'?
 do while oForm.BaseClass#'Form'
   oForm=oForm.parent
 enddo
endif
return oForm

This function may return .null.