A basic example on how to change your stylesheet dynamicaly! I will use a dropDown list to control the environtment!
Assuming that you have 4 different .css ( default, red, blue and green ) on your directory!
From this line you'll have to replace this with your own stylesheets.
default.css body{ background-color: white; color: black; }
red.css! body { background-color: red; color: black; }
blue.css! body { background-color: blue; color: yellow; }
green.css body { background-color: green; color: white; }