AddGadgetItem Flag GADGETITEM_TOGGLES dosnt Work

' createlistbox.bmx
Strict
Import maxgui.Drivers
Local window:TGadget
Local listbox:TGadget
window = CreateWindow("My Window", 30, 20, 200, 200)
listbox = CreateListBox(4, 4, 100, 80, window)
AddGadgetItem(listbox, "MyItem 0", GADGETITEM_TOGGLES) '<<<<<<<<ERROR
AddGadgetItem(listbox, "MyItem 1", GADGETITEM_TOGGLES)
SelectGadgetItem listbox, 0
While WaitEvent()
	Print CurrentEvent.ToString()
	If EventSource()=listbox
		Print "SelectedGadgetItem()="+SelectedGadgetItem(listbox)
		If EventData()<>SelectedGadgetItem(listbox) Print "error with skidracer"
	EndIf
	Select EventID()
		Case EVENT_WINDOWCLOSE
			End
	End Select
Wend