$cookie error

Hi All, I'm using $_session to store user name and status and the session is used as key to access some pages and I set the cookie variables like this : setcookie ("name",$user_name, $time+3600); setcookie ("status",$status, $time+3600); and the authentication of the session variable like this : if(!isset($_COOKIE['name']) or !isset($_COOKIE['status']) or $_COOKIE['status']!='user') {header("location:sign_in.php");exit;} else {$user_active=$_COOKIE['name'];$status=$_COOKIE['status'];} But the problem is that sometimes when I link to (eg : product_add.php require $_session) it success but in the other time it's fail ...(although I do it continuous ...I mean after the 1st time success and 2nd times fail)... it couldn't be the problem of $_session lifetime ... I think. I can't find "why" such problem occurs.... anyone hav the same problem?? thanx anyway... Flame (sorry if out of topic)...