About problem in my php code

Thanks for all help from Philp and Richard. I learned the session issue and fixed the problem. For some reason, I could not receive any email from this list. I checked the message only from the list's web site, but did not receive any (my post, reply, or any other posts) in my mail. I did receive the "subscribe confirmation message" though. I have to check the web site to see posts, but could not "reply" from there. I do have spamblock software, but I don't see any mails from this list in the blocked-mail folder. Can the manager of this list give me some help? Thanks! Hongwei Li