Hi

Assuming the ID number is in column A on both sheets

=IF(MATCH($A2,Sheet2!$A:$A,0),"Attending","Not Attending")

Change the ranges to suit, and copy down the column as far as required
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Regards
Roger Govier

PA wrote:
Using Excel 2007, I have two worksheets, one has a list of national
membership, including an ID # in column A, the other will contain the similar
information of individual who are attending a national conference. I need to
find those on the membership list who have not registered for the conference.
Thank you