how do i make the icon change direction when it moves?
here's my code so far, which i just started:

world
mob = /mob/spybot/snaptrax
turf = /turf/floor

turf/floor
icon = 'Floor.dmi'

mob/spybot/snaptrax
icon = 'Snaptrax.dmi'
icon_state = "NORTH"
proc
North()
icon_state = "NORTH"
proc
East()
icon_state = "EAST"
proc
South()
icon_state = "SOUTH"
proc
West()
icon_state = "WEST"
Someone help plz.