Pls help me in panning content (left/right)

I need help in panning my content from left to right (with stop as intervals) then right to left (also with intervals)

I attached the .fla/.swf and I explained the steps I did below and I need help in Number 5. Thanks in advance!

What Ive done so far…

  1. I created an mc (name: “content”)
    Notice in this mc, I layout 4 sets of text (like a page) from left to right

  2. I created another mc (name: “pancontent_mc”)
    -I added a layer for “content” and created a motion tween for it to pan from left to right
    -I created a mask layer on top of “content” that will show 1 set at a time
    -I created an action layer that has total of 4 stops(); on each frame where the 4 sets of text will show directly under the mask.

  3. maintimeline
    -There’s only 1 layer. I placed an instance of buttons (left/right) and an instance of “pancontent_mc”

  4. actions for right button, works fine and stops on each set of text.
    on (release) {
    this.pancontent.play();
    }

  5. actions for left button - none. I havent figured this out yet.
    what i want to happen is…

on (release) {
this.pancontent. - something like play previous frame until stop…
}