well to 'lock' a topic you need to be a forum moderator. You can close your own threads that you create though by simply clicking the 'X' in the top right hand corner of the thread.
No, you didn't :lol: Locking threads can only be done by myself or a moderator. The "X" you see on some of your posts does not "close" a thread, it deletes the last reply on a thread (if that last reply is yours). If it is the first, last and only message on a thread, then the entire thread is deleted if you delete your post.