Highlight Menu On Scroll

Hello, this is the best free theme I use so far. I also recommend my friend to use it. nice work.

Here my question.
how to make the menu link hightlight when I scroll to the spesific section? I dont know how to describe it, this Highlight Menu On Scroll Link will describes everything i want. Or maybe where i must put the code in the attached link?

Thanks for your assistance!

you can use x:active { }
statement for that for more details: