How to set cookie which does not expire in PHP?

how do i set cookie for unlimited time. i am using it to automatically log in the users. and i want cookie not to expire till they logout. how do i do that in PHP?

setcookie("x", "y", 9999999999);

is this 999999999 some special value or you are just setting time to some big value so it does not get there???

There is no such thing as a not expiring cookie. You have to set the expiration date to something high so that it doesn’t expire early, the max is in the year 2031 or so I think.

ok thanx. that would do.
thanx for your time everybody.