Hi Dave
A validate button sounds fine to me.
The input cells a C2, C4, C8, C9, C10 , C11 and C21.
I have broken down the calculations into 5 possible senarios.....using cells
as below.
Calculation 1
C2= Must have
C4= Must have
C21= Must have

Calculation 2
C2= Must have
C4= Must Have
C8= Must Have
C11= Must Have
C21= Must Have

Calculation 3
C2, C4, C8, C9, C11, C21 all must have

Calculation 4
C2, C4, C8,C10,C11, C21.

Calculation 5
C2, C4, C8, C9, C10, C11, C21,
Cells C9 and C10 are optional...but must be filled if there is data present.
It would be nice to find out a way to confirm if the data were
entered.......by some form of text message.

Note
Cell C24 shows a "#Value!" error if cell C24 data is not entered.

Dave I am in the UK, London GMT time.
How do I create the validate button within excel?

Hope you can help





"Dave O" wrote:

Good morning, Dermot-
I didn't mention the *easiest* event: orchestrate one. Advise your
users they must press the "Validate" button at a certain point in data
entry. Adding a button to a sprdsht is easy, and just as easy to
assign code to that button.

If that's amenable to your process, it's just a matter of stepping
through the required logic. Your post says
entered in a top to bottom order. They are either all required for a full calculation or only three under certain circumstances
.... and
if the code could incorporate some form of logic..cells (A AND B AND C) OR(A And B......And F)

This is absolutely do-able: if you can determine how many circumstances
are possible and what cells are required in each given circumstance,
then we can write the code to accommodate it.

How do you feel about the "Validate" button?

And just for grins, what is your continent/time zone? I am in North
America, Eastern Daylight Time.

Dave O