Scroll bar problem

Hello,

I have encounted some problems in using the scroll bar with a dynamic text field.
Problem:
I don’t know why when you scroll the scroll bar, it sometimes does not let you drag until the end… could you try and advise what the problem is? thanks!
http://www.eocreative.com/eddie/album/cambodia_journey/agreement.html

I just simple set this script on the timeline to load
T_C.htmlText =“text content…”
and then the scroll bar with the parameter (target textfield) pointing to the instance name of the text field (T_C)

Thanks!