Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column < 1 Then Exit Sub
If WorksheetFunction.CountIf(Columns(Target.Column), Target) 1 Then
MsgBox "Duplication"
Application.EnableEvents = False
Target = ""
Application.EnableEvents = True
End If
End Sub


Gord Dibben MS Excel MVP


On Wed, 9 Dec 2009 04:43:01 -0800, billy
wrote:

How can I make this work on a specific column? I want duplicates to be
allowed in every column except A

Billy

"Stefi" wrote:

Data validation is used for drop down list therefore you need an event macro
for that:

Private Sub Worksheet_Change(ByVal Target As Range)
If WorksheetFunction.CountIf(Columns(Target.Column), Target) 1 Then
MsgBox "Duplication"
Application.EnableEvents = False
Target = ""
Application.EnableEvents = True
End If
End Sub

Post if you need help to install it!
Regards,
Stefi

„Craig” ezt írta:

If i have a range of cells from A1:A100 and the same drop down list of names
in each of those 100 cells how do i prevent staff from selecting the same
name twice within that range?

For example i want to avoid someone selecting a name in cell A3 and then
selecting the same name further down the spreadsheet at say A70.

Is it also possible to display a message saying that a duplication has been
attempted?

Thanks in advance
Craig