In testing this I've also had problems.

THREED('Jan ''08:May ''08'!$K$6:$K$8)

I don't know what those extra quotes are for but I removed them and tried
this:

=SUMPRODUCT(--(THREED('Jan 08:May 08'!K6:K8)=K12),THREED('Jan 08:May
08'!L6:L8))

This returns a #REF! error.

If I rename the sheets and remove the space it works** :

=SUMPRODUCT(--(THREED(Jan08:May08!K6:K8)=K12),THREED(Jan08:May08 !L6:L8))

** It works until I change data in the range L6:L8 then it returns a #VALUE!
error. If I edit the formula cell (double click then hit enter) it once
again works.

I wanted to post this at the forum but I don't speak French. I've also had
some user interface problems using Morefunc in Excel 2007. If (I) you goto
the Formulas tabMorefunc groupFunctionselect a function, sometimes the
user form doesn't display.

--
Biff
Microsoft Excel MVP


"Ron Rosenfeld" wrote in message
...
On Thu, 19 Jun 2008 07:53:04 -0700, Eddy Stan
wrote:

HI,
CAN YOU PL FIX THE ERROR - I GET REF! ERROR
=SUMPRODUCT(--(THREED('Jan ''08:May ''08'!$K$6:$K$8)=K12),THREED('Jan
''08:May ''08'!$L$6:$L$8))
this is only for testing before i use on required big range.
thanks in advance

You should let Excel create the reference instead of typing it in
yourself.

In the past, Excel has not always behaved properly when sheet names
contain
apostrophe's (single quotes). It seems that THREED has these same
limitations.
Can you remove the apostrophe from the sheet names?
--ron