=ISNUMBER(MATCH(A1,Sheet2!A1:A10000,0))

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

"WTG" wrote in message
...
Is there a function like lookup that will return a true/false value.

if this number on sheet 1 a1 is found anywhere on sheet 2 a1:a10000,
return a value of true or yes, if not return a value of false or no.

Thanks

Wally