Hissingsid - 4:02 pm on May 23, 2012 (gmt 0)
Incidentally since you can clear cookies simply by setting the expiry date to an earlier date you just need to write a cookie with the same name and earlier date in order to clear it so the following simple code does all you need for GA cookies.
<!-- IN DOCUMENT HEAD Just change yourdomain -->
function delete_cookie ( cookie_name )
document.cookie = cookie_name + "=; expires=Thu, 01-Jan-70 00:00:01 GMT; path=/; domain=.yourdomain.co.uk;";
<!-- Put this where you want it in the page -->
<p><a href="<!-- Link to cookies deleted page -->" delete_cookie('__utma');delete_cookie('__utmb');delete_cookie('__utmc');delete_cookie('__utmz');">Clear Cookies</a> </p>