session and header("location....")

Hi everyone, Thanks for looking at my question! Well, i just made a script that firstly check's up username and password (log-in script) then next if the user enteret the correct information a session is set like this: session_id($sessid); session_start(); $_SESSION['ngskdsngjkla465gfdh'] = "LOGETIN-TRUE"; But then when this session is set it changes from the log in page to the real password-protected page. I tried with a normal header location, but it did'nt work, so i tried to look at php.net about sessions, it says that you're had to transfer the sessionid to the next page. Now i'm trying that, but it just wount work... The header location im using looks like this: header("Location: http://www.domain.tld/admin/index.php?PHPSESSID=".sessid); And i also tried with: header("Location: http://www.domain.tld/admin/index.php?PHPSESSID=".$sessid); But none of them will work....i hope you will look at it, and tell me if you have a solution. Thanks folks. Regards. Lars Rasmussen