Actionscript: horizontal movement (loop)

I'm working in a basic animation to make a basic animation of pictures. I have a .Fla file that contains the animation from left to right and an infinite loop. I want the images to move in the opposite direction, from right to left, and I don't know how to do it. I also want another action. when the mouse is over the animation, it stops and when the mose is not over the animation, it continues. The file is in Flash 8 format. The dimensions of the scene are: 941px(width) X 100px (height) for more information, please watch the next video: [login to view URL]