Try this

Select A1:C1 with A1 active cell

Data Validation Allow Custom

and apply this formula

=ISNUMBER(A1)*COUNTIF($A1:$C1,A1)=1


--
daddylonglegs
------------------------------------------------------------------------
daddylonglegs's Profile: http://www.excelforum.com/member.php...o&userid=30486
View this thread: http://www.excelforum.com/showthread...hreadid=505926