Hi Colin

One way would be to create a named range called Mydata using
InsertNameDefine and including your range of 12 cells as the Refers to
item.
Then
=IF(COUNTA(Mydata)<12,"You need more data",your_formula)

--
Regards

Roger Govier


"Colinhp" wrote in message
...
I want a SUM formula to occur in cell B34 that includes the following
cells,
providing they are not blank.
O12,O13,O23,O24,O36,O37,O45,O46,O56,O57,O65
and O66. These cells have a drop-down selection of numbers from 1-5,
and
have data validation and conditional formatting set to red prior to
them
choosing from the drop-down list.
I can nest ISBLANKO12:O13 in an IF function and if False have the SUM
formula occur, but how do I also include these cells
(O12,O13,O23,O24,O36,O37,O45,O46,O56,O57,O65 and O66) in the IF
function too?
If any of these cells are left blank by the user I want a message to
appear
informing them that they must enter data in all of the cells before
they find
a result shown in B34.
This message is not to be shown before the user starts entering data
in the
cells.