If the error is #NA then it should be ISNA used, else ISERROR may hide other
inadvertant errors.

--
Regards
Ken....................... Microsoft MVP - Excel
Sys Spec - Win XP Pro / XL 97/00/02/03

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It's easier to beg forgiveness than ask permission :-)
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"John Michl" wrote in message
oups.com...
Try
=IF(ISERROR(VLOOKUP,a1,B1:C10,2,FALSE),100%,VLOOKU P,a1,B1:C10,2,FALSE)

- John