Setting Things Up
Before we get down and dirty though, let's set up our FLA:
First, create a new flash document and then create (3) layers: actions, scroller, window.
Now, create a movie clip to hold the image we'll be scrolling. If the library panel isn't already open, press Ctrl+L. Then right click inside the library panel and choose New Symbol. Give it a name, I chose mc_pic and make sure to select Export for Actionscript.
Create (1) button to use as your scroller.
Create (1) rectangle graphic symbol the size you want your window (optional).
Convert your graphic symbol to a movie clip (Press F8).
Place your new movie clip on the stage on the window layer. Name the instance. I used mc_win.
Next, we'll get into a little actionscripting...