Continuing my  blog titled Themes in Whidbey. I would like to mention some great points I did find out today about Whidbey featrures.  
How many times have you got sick of developing Sites which have themes????  
I mean every page u create has to have, maybe in ASP, something like
<link href="<%=Session["ThemeFile"]%>.css"/>
I have been doing since a long time. Do mention if you have a simpler method of defining a variable CSS for your page!!! Whidbey simplifies this further. Now in ASP.NET, all you will have to do is  

• Create Themes directory, if not aldready present,
  
• Create a directory for each theme required, maybe Black, Gray,etc.
  Dump your CSS files into this directory.
  
• in Page_PreInit method define the Theme as Page.Theme="<Theme directory Name>". Further can be made into Page.Theme=(string)Session["ThemeType"]
  

and viola, your theme management is take care by ASP.NET
When you want to change the theme, the string to be passed to the Theme property should be changed. Is'nt that great.

But beware of using the skinId property for any controls. The complexities were aldready mentioned in the other blog.
Anwyay go ahead and play around. Until the next time, happy theming!!!