I'm trying to programatically set the numberFormat property. on mouseUp repeat 4 times put "#" after t end repeat put "set the numberFormat to " "e& t "e into tDo do tDo put 5+1 end mouseUp puts just "6" in the msg now if I try: on mouseUp set the numberFormat to "####" put 5+1 end mouseUp It puts the expected "0006" Any ideas why??