Access 97 Form

I have a Form called “Secretary Changes”. This form has a subform called “ALLDUE Subform” with dependent records. When I click a command button on “Secretary Changes” I want the following to happen:

On the subform the field called “Dues_Numb” should be updated to:

Take the highest year from ALLDUE and show only the last 2 characters(2002=02) plus a hyphen and the IDNUM from ALLDUE…

Example:
You are looking at idnum # 111 ‘s record.
You click the command button and the “Dues_Numb” field changes to “02-111”

I used Right$([Year],2) but I keep getting errors???

Can you help…
Alan
abramowitza@coned.com