Mike wrote on Thu, 25 Mar 2010 07:05:01 -0700:

You can use this macro

Sub Liminal()
Dim FillRange As Range
Set FillRange = Range("A1:A20")
For Each c In FillRange
Do
c.Value = (20 * Rnd) + 1
Loop Until WorksheetFunction.CountIf(FillRange, c.Value) < 2
Next
End Sub
--
Mike

When competing hypotheses are otherwise equal, adopt the
hypothesis that introduces the fewest assumptions while still
sufficiently answering the question.

Come on Mike, William of Ockham said essentially that a long time ago
:-)

--

James Silverton
Potomac, Maryland

Email, with obvious alterations: not.jim.silverton.at.verizon.not