Try running a search on Google for 'css style switchers' or 'css style switch'. There are many options to choose from. You may also want to check out the code used on http://www.meyerweb.com (you may need to poke around to find it).
Alex
Alex
[ bald_technologist on the IRC channel (irc.freenode.net): #eZpublish ]
We used this technique on our eZpublish site http://www.designit.com.au/ There are three styles to choose from. It's a great way to show the power of CSS to clients.