Controlfocus is not working

[wooddy 0]

I trying to put focus on a control that's on a sub form. Can someone show me what I am doing wrong?

AI.ControlFocus("Microsoft Access", "", "[CLASS:OFormSub; INSTANCE:4]")

>>>> Window <<<<

Title: Microsoft Access

Class: OMain

Position: 48, -4

Size: 980, 776

Style: 0x17CF0000

ExStyle: 0x00000100

>>>> Control <<<<

Class: OFormSub

Instance: 4

ID:

Text:

Position: 80, 398

Size: 912, 161

ControlClick Coords: 178, 153

Style: 0x56000000

ExStyle: 0x00000000