How to create a dynamic navigation bar which follows you when you reach certain location

Question

I want to create a navigation bar similar to this site\'s:

http://www.mysupermarket.co.uk/#/shelves/top_offers_in_asda.html

Can anyone tell me how to create

Answer 1

Note: this won't work with the Android 2.3 browser; position:fixed will not behave as expected - it kinda of temporarily attaches its position to the scrolling element before jumping back to the top.