Help with scrolling platformer

well iv been looking for scrolling tutorials for AS2, but most are from before AS2 and dont work. can someone help? i want to achieve an effect similar to this, were when you walk right you keep moving right but you get closer to the left and more on the right is seen. and if you walk left you get closer to the right(the camera)

video example: http://www.youtube.com/watch?v=hwcLIGLOpqg