data validation or message box

Giganews Newsgroups
Subject: data validation or message box
Posted by:  maryj
Date: Wed, 10 May 2006

Users will enter in Column B the order date. In Column C they will enter the
expected ship date. If the expected ship date is less than 8 weeks (not
including weekends), I would like a message to pop up. I'm using the formula
=IF(B7="","",INT((C7-MOD(C7-O7,7)-B7+7)/7)) (O7 contains the value indicating
that Sunday is the first day of the week). Is this possible with data
validation or do I need to use a message box? If I need a message box, I am
not very proficient in VBA so would need some guidance on that. Thanks so