Originally Posted by
dblife
You need to create a table with a unique primary key, a field for time A and another for time B.
Use this to create a query and use the DateAdd() function to calculate the difference between the two.
Use this query as the basis for a form.
It is not usually 'good practise' to store values you can get Access to calculate 'on the fly' whether in a query as part of a form or report.
As for setting an autonumber field to zero, there is a way but what is the point, the user is never meant to see an autonumber field.