Projectseven.com: Tutorials: PVII Write Styles is a free tutorial and extension that “allows you to write a style sheet dynamically – before your page content loads.”
Project Seven says, “This tutorial will show you how to take a popup Layer controlled by Dreamweaver’s default Show-Hide Layers behavior and make the contents of the Layer accessible to all browsing devices by using the PVII WriteStyles Command to style it dynamically.”