Check for Duplication over two fields
I am new to filemaker and having a good time working my way through some interesting challenges. The problem I can't get past at the moment is I am in a table and I am trying to stop duplicate entries being created in a table, but only if its a duplication of two fields.
In the table there is a name and a year field. The name comes from a field in another table, the year is a restricted field that only allows 4 digit numeric number. I want to be able to create an entry for a person in a particular year, but only one entry per year. For example.
You can create a record for 'Bob' in '2012', then a record for 'Bob' in '2013', 'Bob' in '2014' etc etc.
But if there is already a 'Bob' in '2015' I want it to throw up an error and not create the entry. Then tell the person an entry for this person already exists for this year.
How can I do this check over two fields?
Thanks in advance.