Reading a Cookie
<?php echo $_COOKIE['user']; ?>
Deleting the Cookies
<?php setcookie('user',''); ?>
<? setcookie('user','', 
             mktime(12,0,0,11,22,1970)); ?>
Other Optional Paramters
Path, Domain, and Secure parameters can also be set to restrict a cookie to a certain path, domain or in the case of the Secure parameter, limit the cookie to only be set if the request came in over an SSL connection.