Define theme for Google Website optimzer dicussion

[Timpet]

Hello.

I got inspiration from another tread to this.

I have realy bin trying to find a reasonable way to A/B test using website optimzer.

The inspiration gives me:

if (isset($_GET['theme']) AND $GET['theme'] == 1) {
   define('_THEME_NAME_', 'theme1');
   $cookie->theme = 1;
}
elseif (isset($_GET['theme']) AND $GET['theme'] == 2) {
   define('_THEME_NAME_', 'theme2');
   $cookie->theme = 1;
}
elseif ($cookie->theme == 1)
   define('_THEME_NAME_', 'theme1');
elseif ($cookie->theme == 2)
   define('_THEME_NAME_', 'theme2');

Im not sure that i can add to the cookie / set the cookie like this, but perhaps others have an ideer, as this is realy need for those how would like optimze there site