Help with creating a scroll bar

Hi I'm trying to add a scroll bar to the Menu Page section of this template and I'm having a very hard time in doing so. I was reading a tutorial and got lost during the masking part. Can someone please help me out and give me guidance on what to do? It would be greatly appreciated

The page where i need to create a scroll bar is inside "pages" and its on the Menu section.

Attached is the template

My work is located in main2_v8CS6FINAL.fla
https://hotfile.com/dl/175464505/ed2...ource.rar.html

Virus total scan:
https://www.virustotal.com/file/c896...is/1349764246/

please any help? I think the scroll bar is not working because it is already inside a mask ?