Many thanks for taking the time to reply, much appreciated.

"JulieD" wrote:

Hi

one option is to use conditional formatting that makes the three cells go
red or something if data is entered into more than one of them ... select
the cells and choose format / conditional formatting from the menu
choose formula is
type
=COUNTIF($C6:$E6,"<"&"")1
click on format and i would personally set a pattern (fill colour, e.g. red)
click OK twice
and test

Cheers
JulieD

"McKenna" wrote in message
...
I have just come back to excel after a couple of year away, and fustrated
that I can't remember how to do things!

I have three cells C6(provisional),D6(confirmed),E6(rejected), I want to
be
able to input a value to one cell, but only if the other two are blank. A
user will need to change the value according to the progression of the
order,
but I want the safeguard of not having a value in more than one cell.
I've
tried an IF statement, and a IF AND statement, but still can't get it. I
would welcome any help.