Scrollpane help

I hope this isn’t too dumb of a question, I have searched around for an answer but can’t seem to find exactly what I am looking for

I have created a movieclip in my .fla and named it moviescroll_mc and gave it the same instance name. I want to use the scrollpane component so that the user can scroll the movie vertically, since it is too large to fit on the stage.

I was trying this code, but it didnt work

aSp.source = moviescroll_mc;

I’m an AS3 noob so an help would be appreciated!