automatic scrolling a field to the bottom when Text is entered

[Björnke von Gierke]

I already did this once. It included an "oldText" property, a "send to 
me in 1 second" handler and some calculating of the "formated height".
  but I do not want to do it like that again, there must be a simpler 
solution to scroll a field all the way down when text gets entered 
(whether by hand or by script)

thanks

Björnke