cookie problem..-.-a

[Anon]

i made cookie when user login:

        $time = 3600*12;
        $date =  gmstrftime("%A, %d-%b-%Y %H:%M:%S", time()+$time);


        header("Set-Cookie: login_id=$login_id; expires=$date GMT;\n\n");
        header("Set-Cookie: login_name=$login_name; expires=$date GMT;\n\n");
        header("Set-Cookie: login_class=$login_class; expires=$date GMT;\n\n");
        header("Set-Cookie: login_level=$login_level; expires=$date GMT;\n\n");
        header("Set-Cookie: login_pw=$password; expires=$date GMT;\n\n");

/***************************/

problem is that after login cookie works and next linked page it doesnot work..
(cookie is deleted )

and user login again ..
all cookie works very well ..

why happen this problem?