For an explanation of the double unary usage, see:

http://www.mcgimpsey.com/excel/formulae/doubleneg.html

and

http://tinyurl.com/5fvwo

To learn about SUMPRODUCT, see:

http://www.xldynamic.com/source/xld.SUMPRODUCT.html

HTH
Jason
Atlanta, GA

-----Original Message-----
I have used the sumproduct function a lot and thinks it
is very good. My
problem is that I do not know the functions of different
characters that can
be used in the sumproduct function

Ie. what is the "--" in front of a sumproduct
function : "Sumproduct(--(xx
and when to use "*" and "+" and ",".

Does anyone have any "guide" to sumproduct that can
explain theese things
and probably other things?



--
Peter B
Norway
.