Hello,

I'm not sure what I'm doing wrong but I hope someone can
help me. I have a UDF that I want to calculate a value
for me. The normal Worksheet display of the function
would be =IF(ISERROR(AVERAGE(E5:E6)),"",AVERAGE(E5:E8))
I would like this to be a user defined function letting
the range be selectable by the user. I've created Each
individual part of the function and it works correctly but
for some reason when I try each piece together it doesn't
work.

If you run a macro to record the steps of manually
inserting the function the VB looks like.

ActiveCell.FormulaR1C1 = _
"=IF(ISERROR(AVERAGE(R[-16]C[-1]:R[-15]C[-
1])),"""",AVERAGE(R[-16]C[-1]:R[-15]C[-1]))"

I've tried many ways to turn this into a function.
Like I said I can take each individual function and have
it work correctly in a UDF but to combine the IF, ISERROR,
and AVERAGE functions and then assign this value to the
Function name just doesn't seem to work. I've debugged and
it has had the correct true and false values for data that
I tested it on. Oh well, hopefully someone knows.

I would also like to create UDF's for these functions as
well.
=IF(sheet!F3="N/A","N/A",IF(sheet!F3="","",NETWORKDAYS
(sheet!D3,sheet!F3,sheet!D3)))

=SUM(IF(sheet1!$C$2:$C$500="AA",IF(sheet1!
$D$2:$D$500<=DATEVALUE("8/31/2004"),IF(sheet1!
$D$2:$D$500=DATEVALUE("8/1/2004"),IF(sheet1!
$B$2:$B$500="DD",1,0),0),0),0))

I've got a few more questions but I'll hold off for now.
Thanks to whom ever can help me.