Form date field with warning

[Aosmond]

I have a form that has three date fields [WeekOne], [WeekTwo] and [WeekThree]. When someone enters date on the first field [WeekOne], in the second week I want to be defaulted to seven days from the first week. For example if I type 01/01/2013 in week one, I want the week two field to be defaulted to 01/08/2013, but also I want to be able to change it. But if I decide to change and I type date that is more than 7 days or less than seven days from the first week I want to see a warning saying "Are you sure this is the correct date" and by clicking Ok I can make the changes. Also I would like to have the same situation in week three. it also should be seven days from the week two. can you please help how to code this in the form. I have MS Access 2003. Thank you

[June7]

Code in AfterUpdate event of WeekOne could populate the WeekTwo and WeekThree fields. Something like:

If IsNull(Me.WeekTwo) Then Me.WeekTwo = Me.WeekOne + 7
If IsNull(Me.WeekThree) Then Me.WeekThree = Me.WeekOne + 14

Then code in BeforeUpdate events of WeekTwo and WeekThree could ask user:

If MsgBox("Are you sure this is the correct date?", vbYesNo) = vbNo Then
Cancel = True
EndIf