This is the default /order/template/header.html file.

You can use a single header.html file for all steps or setup one for each step.

1header.html = Domain Whois Form Page
2header.html = Domain Whois Results Page
3header.html = Package Selection Page
4header.html = Add-on Selection Page
5header.html = Display Cart Totals, New & Login Form
6header.html = Display Cart & New Order Form & Confirm Order
7header.html = Process Order Duplicate Error
8header.html = Process Order Success