def tower():
    #turns about right
    tank_pair.on_for_rotations(15, 0, 1)

    us.mode = 'US-DIST-CM'
    #While it hasn't pressed the top button
    while not ts.value():
        distance = us.value()/10
        #greater than 60cm
        if distance > 60:
            #just slowly move forward
            tank_pair.on_for_rotations(20,20,1)
        else:
            #is than than 60cm
            tank_pair.on_for_rotations(-50,-50,1)
            tank_pair.on_for_rotations(100,100,1)
            break

    #at this stage we should of hit the bottle, now just go forward ?
    while cl.reflected_light_intensity < 30:
        #we should be on the, black finish title, just move forward
        tank_pair.on_for_rotations(50,50,1)
    #Move back to the back title
    tank_pair.on_for_rotations(-10,-10,1)
    #Stop
    tank_pair.stop()