I don't have time right now to post a full answer, but here is the answer to a similar question.
Basically the idea is to create a [Sequence #] field which is based on a formula which will start off the numbering by Department at whatever number you want to start at.
var number StartNumber =
Case([Department Number],
"10",1234,
"20",2000);
Max($StartNumber,[Sequence # snapshot])
Then we make a field called [Sequence # plus 1] which is the formula of [Sequence #] +1, and make a summary of the Maximum that field.
and then do a lookup back down to the Antiques Table and then take a snapshot of that field called [Sequence # snapshot]
By doing a snapshot we ensure that the numbers don't all get jiggled down when a record is deleted.
The actual Serial # we display is this formula.
[Department Number] & "-" & Right("00000" & ToText([Sequence #]),6)
The concept is to have the contracts be children of the projects. I'm sure you already have that setup. Then you do a summary maximum and look that up down to the child ggain but the magic trick is to snapshot the field. Look up the help on snapshot fields.
Post back if you get stuck and need more help.
Btw, that is not a newbie question. It's a question with a tricky answer.
