Custom Scrollers for Dynamic Text?

Okay i did the tutorial on dynamic scrollers

http://www.kirupa.com/developer/mx/dynamic_scroller.htm

my problem is they have you use the components and don’t tell you how to create custom scrollers. I need to have just one button that will let me scroll up and down by clicking and dragging…no up and down buttons just a 15 px x 100 px bar that will move up and down depending on how much data is loaded in the dynamic text box.

also the data will be in PHP i didn’t know if that changed anything.