See if this works for you:

=IF(ISNA(VLOOKUP(K16,PR,3,0)),IF(ISNA(VLOOKUP(K16, nonPR,3,0)),"",VLOOKUP(K16,nonPR,3,0)*1000),IF(ISN A(VLOOKUP(K16,nonPR,3,0)),VLOOKUP(K16,PR,3,0)*1000 ,(VLOOKUP(K16,PR,3,0)+VLOOKUP(K16,nonPR,3,0))*1000 ))
--

HTH,

RD
================================================== ===
Please keep all correspondence within the Group, so all may benefit!
================================================== ===


"DC" wrote in message
...
Thanks Bob, but I still get the 'too many arguments' message.

"Bob Phillips" wrote:

Put the VLOOKUP formula in their own cells and reference these cells.

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my
addy)

"DC" wrote in message
...
I get an 'you've entered too many arguements' error message with my
formula
below. What do I need to do to get it to work?

I have 2 tables, PR and nonPR, and I want to add values together where
the
left most strings match in each. If only one table contains the string
then
take that value, if neither do then return a blank.

=IF(ISERROR(VLOOKUP(K16,pr,3,FALSE)),if(iserror(VL OOKUP(K16,nonpr,3,FALSE)),"",VLOOKUP(K16,nonpr,3,F ALSE)*1000,if(iserror(VLOOKUP(K16,nonpr,3,FALSE)), VLOOKUP(K16,pr,3,FALSE),VLOOKUP(K16,pr,3,FALSE)+(V LOOKUP(K16,nonpr,3,FALSE)*1000))))