Conditional Movie Play

Hey… I’ve been trying for a while now but I can’t seem to get a small movie clip to play when my dynamic text field is scrollable.

I have scroll buttons to use when I have enough text but I couldn’t make them invisible when there is insufficient text, even using AS that had worked on a different project. So I decided to make the buttons pulse when they are needed, again I cannot make it work.

Im using this:

if (main_txt.scroll>0) {;;

Where “main” is the name of my dynamic text field and “upactive”/“downactive” are the pulsing movie clips.

Any ideas why this isn’t working?