UIScrollView: paging horizontally, scrolling vertically?

Question

How can I force a UIScrollView in which paging and scrolling are on to only move vertically or horizontally at a given moment?

My understanding is that

Answer 1

This works for me everytime...

scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * NumberOfPages, 1);

Answer 2

Guys it is as simple as making the subview height the same as the scroll view height and the content size height. Then the vertical scrolling is disabled.