Can I make the header only go across the whole web site ( 100% Width ) when at the same time have the main part of the site at 1024px ?

example on the very top here http://www.movieweb.com/

thanks!

You can use a background image such as they did in your example for the full width dart background. You could also use an image wrapped in a div in HTML Inserts: Body Top box and then use CSS to position as you want.

Another idea is here.