=IF(COUNT(A1,B1)=2,B1-A1,"your error message")
--
David Biddulph


"John" wrote in message
...
Hi,
In Cell A1 and B1 there are dates, cell C1 calculates the difference
between
these dates and displays it as days.
How can I have a function in cell C1 which will notify me if there are any
dates not entered. i.e. "Date Required" or "incorrect Format"

Regards

John