setcookie('login','12345',0,'/','.abc.com');
session_set_cookie_params(0,'/','.abc.com');
session_start();
$_SESSION['login']=12345;
setcookie('login','12345',0,'/','.abc.com');
session_set_cookie_params(0,'/','.abc.com');
session_start();
$_SESSION['login']=12345;