Change web site theme for client from MaterPage

I need to change website theme (css) by clicking button on Master Page.

   protected virtual CSSClick (_sender : object,  _e : System.EventArgs) : void
   {
       //Session("The开发者_StackOverflow中文版me") = "Advanced";
   }

Google & MSDN didn't gave me the answer :( So no matters on C# or VB.NET , just how to make it ?

thank you.

I remember that Marco Bellinaso explained this in his book ASP.NET 2.0 website programming (problem-design-solution). In the book he is building a website called the Beerhouse. The source code for the Beerhouse project is is on codeplex:

http://thebeerhouse.codeplex.com/releases/view/127

If it's just based on CSS then I suppose you could wrap the CSS link tags in placeholder controls and show/hide them accordingly in the button click event.