UIScrollBar - Help?


I have a UIScrollerBar on the Stage that attaches to a Dynamic Textbox named ‘dTText’ - I am filling dTText with "text
" each time something is clicked and when the text fills past the bottom of the Textbox the scroller works fine, however:

When the scroller starts to grow as the content does, how can I have the scroller be snapped at the bottom? Eg: Similar to MSN / Chat services, as the messages go down the scoller grows but does not stay at the top, instead it goes to the bottom and you can scroll up to see your previous comments (this is what I would like).