On your open form, put a onKeyDown event. Trap for keycode 33 (page up) and 34 (page down). When these cases arrise, produce whatever result you desire, i.e. Me.Form.SetFocus
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = 33 Or KeyCode = 34 then
Me.Form.SetFocus
End If
End Sub
Hope this helps.