php selecting multiple stylesheets

Hello, I'm trying to set up a web site. This site has multiple stylesheets, one default stylesheet that should be used if the other is not chosen. The second is a high contrast stylesheet and can be selected by user's who need it. I'm also thinking of adding two more for smaller and larger font selections. My issue is I want the high contrast sheet to be used on all subsequent pages and on subsequent visits to the site by user's who have selected it. I thought of using php with this and cookies. I'm using php5 and would appreciate any suggestions, googling has shown some examples, but none are working. Thanks. Dave.