you should have separate tables for threads and comments to threads...then associate the two...like...
thread_id = comment_to_thead_id
(comment_to_thread_id is not the same as the primary key)
then you can display all the comments to just one particular thread...
http://www.yourwebsite.com/viewthread.php?thread_id=9
call up the thread
SELECT * from threads WHERE thread_id = '$thread_id'
and then call up your comments to the thread
SELECT * from thread_comments WHERE comment_to_thread_id = '$thread_id' ORDER by comment_id ASC
like that...hope this helps...vaska