How navigation bar was developed [closed]

[HavocSquad]

I was really hoping someone could help explain to me how the navigation bar on the following site was developed (ie. what client side scripting was used, what css code was used, how it was marked up, etc.):http://liechtenecker.at/Specifically I'm wondering how the navigation bar scrolls up initially as you scroll down the page, then when the navigation hits a certain point (in this case the top of the page), it remains stationary as the rest of the page scrolls behind it.I hope my explaintion and question is detailed enough to get the correct feedback from everyone. If you need me to provide more details, please let me know. I look forward to hearing back from the community. Thx in advance for whatever info you all can provide me with Cheers,AJ