Looping movieClip Problem

Hi everyone,

Recenly, i got a question if i want to do some looping in AS3. I have attached a pic to explain. Since there is left and right button, it is turn the movieclip position x value to left or right. My problem is what is the better way when the current mc is 1, and click left. The movieclip 5 will be attached to left. Since it is animation, the animation will be slowly turn to left but not directly set the x value.

Anyone can help?