PHP/MySQL Question

HI, New to PHP/MySQL, I was wondering if this was possible. I have a users database with an auto-incremented userID field. I have another message database (it's a message board database) - one of the fields is a TEXT field with userIDs separated by carriage returns; eg; if on one record userID 2 and userID 4 have both viewd that record, the data in that field will look as follows: 2 4 I want to construct a SQL query for every user that logs in (I am storing their userID as a session variable) so that I can filter out any messages where a user has already viewed that record. So in the above example that record should be filtered out if user 2 or user 4 has viewed the record. The query I constructed is: SELECT * FROM messages WHERE userID != '$userid' But this will not filter out any records like the one above where the userID in the message database is separaed by carriage returns as above (ie; it won't filter out messages for user 2 or user 4). Hope this makes sense Peter