session_start/session_write_close creates multiple session cookie headers. How to fix this.

Hello again, I Use session_write_close() so the page loads quicker because i use session on multiple place. This because session has protection for race conditions. Now it works very well and i don't have any problems at all. I only see that there are multiple session cookie headers set. I Personally think that one is enough :P. How can i make it so that it just sets just one and not set this header every time i call session_start or session_write_close. Because i don't know when the cookie is set. Thx in advance.