showing Last line of dynamic text box

Hi,

I have a dynamic text box, that i am constantly automatically adding text to, a couple of lines at a time. I have created some buttons using the scroll feature allowing you to move up and down the text. However is there anyway that I can make it so when new lines are added they are shown (ie the botton few lines) rather than it starting at the top of the text box each time?

Many Thanks

Laura