The way to control scrolling is by using attributes like:
for the a TextArea component.
From Flex Help (from within Flex Builder - albeit a bit
tricky to find!):
"The Text control displays multiline, noneditable text. Use
the Label control if you need only a single line of text.
The Text control does not support scroll bars. If you need
scrolling, you should use a non-editable TextArea control."
"The TextArea control is a multiline text field with a border
and optional scroll bars."