move.l	#7,d6			; Gadget ID
	bsr.b	GetGadget		; Get address
	lea	TrackGTags(pc),a3	; TagList
	move.l	WindowHd(pc),a1		; Window Hd
	Sub.l	a2,a2			; NULL (reserved)
	move.l	GadToolsBase(pc),a6	; Lib-Base
	move.w	x,x(a3)			; What to change
	CallLib	GT_SetGadgetAttrsA	; Change it!
	rts