Evan,

Try doing someting like this:

On the last object of your child form in a formset or inclusive on the child's form KeyPress Event trapp your "Tab"

KeyPress Event (for the form or the object)
LPARAMETERS nKeyCode, nShiftAltCtrl
IF nKeyCode = 9
Thisformset.Formxx.Objectyy.SetFocus
ENDIF


Rodrigo