Is form FRMSOKKLIENT called from the When or Valid of some control on another form?

>I´m trying to set focus to a grind when a Button is pushed. But I always get a error:
>
>Nummer: 2012
>Meddelande: Cannot call SetFocus from within a When, Valid, RangeHigh or RangeLow event.
>Radnummer: 3
>Text: THISFORM.GRResultat.SetFocus()
>Metod: CLICK
>Object: FRMSOKKLIENT.COMMAND4
>Module: FRMSOKKLIENT.SCT
>
>
>Is there any one how have an idea whats to do?