Hi Ted,

See Preventing Duplicates On Entry
http://www.cpearson.com/excel/NoDupEntry.htm

=COUNTIF($A$1:$A$50,A1)=1
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HTH,
David McRitchie, Microsoft MVP - Excel [site changed Nov. 2001]
My Excel Pages: http://www.mvps.org/dmcritchie/excel/excel.htm
Search Page: http://www.mvps.org/dmcritchie/excel/search.htm


"Ted Rogers" <ted@hotmail.com> wrote in message news:%23QmTltXsFHA.2008@TK2MSFTNGP10.phx.gbl...
> A colleague runs the car-park lottery for our organisation. She uses an
> Excel spreadsheet witha round 1500 entries. The sheet identifies each staff
> member by means of their exclusive payroll number. The lottery is run 4
> times a year. However, she has a problem in that when a member rings up to
> register sometimes neither her nor the member is able to tell if they have
> registered before. She wants to ensure that it is not possible to enter a
> person twice.
>
> So, what would be ideal, is when she has entered the payroll number if there
> is no pre-existing entry Excel will allow her to proceed to the next field,
> if there is this will be flagged up and further entry would not be
> permitted.
>
> I would be grateful if anyone could point me in the direction of a solution.
>
> Best wishes,
>
> Ted
>
>