How to make a highlighted button when loaded a particular page?

Hello guys,

I have a question after reading and successfully follow this tutorial

http://www.kirupa.com/developer/mx2004/transitions.htm

But i would like to make additional animation for the navigation base on the tutorial.

How do i make an highlight button ,after load a particular page?
For example when loaded page section 2, the button will will highlight the “section 2” button on the navigation.

Any help and guide will be really appreciate.
Thanks