An example:

Setcookies:

  $time = time() + 3600;
  setcookie(“cookie[userid]”, “youruserid”, $time, ‘/’);
  setcookie(“cookie[username]”, “yourusername”, $time, ‘/’);
  setcookie(“cookie[nickname]”, “yournickname”, $time, ‘/’); 

Cancel cookies:

   setcookie(“cookie[userid]”, “”, time()-3600, ‘/’);
   setcookie(“cookie[username]”, “”, time()-3600, ‘/’);
   setcookie(“cookie[nickname]”, “”, time()-3600, ‘/’);