I have a query that returns a record set of letters I have sent to a client. Each letter has its own code to identify it. There is a one to many relationship between the client and the letter table, i.e. a client may receive a number of different letters.
What I am trying to achieve is, when a client has been sent a certain type of letter I do not want any of that clients letters appearing in the record set. So for example if the letter code is "NS" I want to be able to set a criteria that will exclude all codes, be they "AS", ZS" etc.
By setting the criteria LetterCode<>"NS" I'm only excluding letters sent with that code not the others.