I am a little confused by what you want to do but have you thought of using something like the following: eval('iif(yr<0,"BC","AD")')
in the option groups.

Costas

>Hi Steven,
>
>> I expect you're snagging up using the negative/postive model, right? 'Cause it's not an accurate representation - there is no year zero. The first year, buy our reconing, is year One A.D. and the previous year is One B.C., not Zero A.D.
>
>Yes, but no.
>In this application the accuracy is not that precise, so year zero is not a problem. But storing BC as a neg. number, displaying it as an ABS() and representing it as option button has me stumped.
>
>Thanks
>Peter