Registered sessions.

Hi, I have a php page that validates if a username and password are valid. if they are the php page registers and assignes a session variable a value. Then straight after that it automatically calls then next php page using the header("Location: researchpapers2.php"); command. My question is: does the session variable still get passed to the researchpapers2.php page, with the header command? because it doesnt seem to receive a session variable. any advice as to where i am going wrong??? thanx Angelo.