you see how the nav bar only scrolls down with the page after a certain point

 

on http://www.fxpro.co.uk/ how is that done?

crtl + u

 

Every web developers favourite learning tool

 

This developer has even helpfully left in his code comments to make things easy for you.

Haven't looked at the source but it's making use of the position css attribute to fix the header. They monitor the pixels the scrollbar is offset from the top and basically turn on position:fixed.

 

You'll need to get into Javascript + HTML + CSS to mimic the solution...

 

Hope that helps.

im still a little lost???

Just look at the sites source code, everything you need is in the sites main .js file and the css. Web Inspector or Firebug will help you find it