Hi all -


Here's my situation:
I'm creating a database in Microsoft Access 2003 to store animal rabies vaccination information. On the form where the user enters the data, they have to enter the length the vaccination will last (either 1 or 3 years), the date of vaccination (i.e. 01/01/2008), and the date the vaccination will expire (i.e. 01/01/2011). Often times, someone will select 1 Year length for the vaccination but the difference between the date of vaccination and the day the vaccination will expire is 3 years.

I want to make it so that when the user enters 1 or 3 years, and the vaccination date, it will auto-complete the vaccination expiration for them (by adding either 1 or 3 years to the date of vaccination), OR another way for it to be implemented is when the user enters the date of vaccination and the expiration date, it auto completes 1 or 3 years for them (by subtracting the two dates and determining whether it is a 1 year or 3 year vaccine).

I realize that calculating values and then storing them is frowned upon, but all three values have to be stored so that they can be retrieved later for reports, etc, but the data entry skills of some of the staff are sub-par, and I need error correction.

Thanks in advance for everyones help!