I may be wrong, yesfree, put if you're looking to add a vertical scroll bar within a page, it cannot be done with div sections within a page. You'll have to go to frames or use an iframe. From your example it appears frames is the solution you want.

I have no affiliation with this site, but the GoodDocuments.com About Us page is an example of what I think you want to do. The reason there are any (vertical) scroll bars at all is because there is more content to show in one frame than there is in another.

If it happens that your content is going to generate scroll bars in both frames, I suggest re-thininking your approach/design. Users will not tolerate two vertical scroll bars.

Hope this helps.