Continously moving objects in flash 8

I am making a game on flash 8 and I am trying to make balloons move up continously for one level and then making the balloons move up and down for the next. I have tried following the tutorial on this site and i canot get it working . I have also tried to create a motion tween and still no luck. Please could anyone help ? I have sent a copy of my file if that helps

Many Thanks