[jQuery] How do I make an inline anchor link slowly scroll down?

I want there to be an event such that when I click on an inline link
it scrolls down to the anchor slowly enough where it is visible. I
can't find out how to do this. Any suggestions? Here is the effect I
am looking for. Click on any of the five top navigation links on this
Jquery page:
http://jquery.com/demo/thickbox/