I'll start off saying, that you can read more about the script here: http://www.themer.me/css-switch-script

Overwiew: A Simple PHP Script to switch CSS Styles. Has support for default CSS files, additional ones, etc. A pretty neat script and a lot more reliable solution then JavaScript. 

If I may, I'd like to ask just 2 things from you:
  * Please don't sell the script. Link to it, it's free.
  * Please, if you find use to the script, leave a link in the comments section (at my blog), I'd really like to see it in action :)