Try using the 4th argument to VLOOKUP and set it to either 0 or FALSE:

=IF(ISERROR(VLOOKUP(A2,'[Aetna - PPO & Dental Jul
2007.xls]Sheet1'!$A$2:$B$126,2,0)),"",VLOOKUP(A2,'[Aetna - PPO & Dental Jul
2007.xls]Sheet1'!$A$2:$B$126,2,0))


--
Biff
Microsoft Excel MVP


"Teri" wrote in message
...
I have two workbooks; I want to look up the value in column 2 in one
workbook
and put it in column 2 of the other workbook. I am matching the values in
column 1 in each. When I fill down, I get the exact same answer. My auto
calculation is turned on. Here is my formula:
=IF(ISERROR(VLOOKUP(A2,'[Aetna - PPO & Dental Jul
2007.xls]Sheet1'!$A$2:$B$126,2)),"",VLOOKUP(A2,'[Aetna - PPO & Dental Jul
2007.xls]Sheet1'!$A$2:$B$126,2))
Can anyone help?