What's the best way to handle unique date entry?

[mrl]

We’re using a single table to record daily data – the date field is set as the pk so only one record per date is allowed.


If the user enters a date (when creating a new record) that already exists in the table
what is the best way to;
a) avoid the Access error message about duplicate values,
and
b) allows the user to enter an alternative date for the new record?

[June7]

If you want to avoid the standard Access error message, will have to use VBA code.

The user already has the opportunity to enter another value after the error message.