Scrollbar on multple dynamic textfields

I'm having two dynamic textfields updated from an outside textfile which I need to scroll in the same time, the only thing I can do is scroll one at the time with a scrollbar.

Is there any way to scroll both textfields with the same bar at the same time?

I've tried with scrollpanes too but they didn't allow me to check how large the included textfile was to adapt the size, at least I didn't know how to.

Thanks in advance!
Johan