=AND(COUNT($C4,$F4)=2,$C4<100%,$F4<1)
why the AND?

Because we're testing for multiple conditions and they *all* must be TRUE
for the format to be applied.

First we check to make sure there are in fact numbers entered in the 2
cells:

COUNT($C4,$F4)=2 = TRUE or FALSE

If both cells were empty then:

$C4<100% = TRUE
$F4<1 = TRUE

And in that case the format would be applied but I'm pretty sure that is not
what the OP wants to happen.

So, with AND each condition must be TRUE for the format to be applied.

=AND(TRUE,TRUE,TRUE) = TRUE

Any other combination of TRUE/FALSE = FALSE

--
Biff
Microsoft Excel MVP


"Domanda" wrote in message
...
On Fri, 27 Nov 2009 12:03:47 -0500, "T. Valko"
wrote:

=AND(COUNT($C4,$F4)=2,$C4<100%,$F4<1)

sorry to interrupt, but
why the AND?