Feeding text to a scrollpane w/ button clicks

Hello,

I am making an animation that uses a scrollpane. Each time a person clicks the next button they see a new block of information in the scrollpane. The text in the scrollpane is actually coming from a movieclip. So, how can I get a new block of text to populate in the movieclip and hence in the scrollpane. Also the scrollpane would have to scroll down with each new block of text.

I hope that makes sense.

Thanks in advance.