I got the code above to work. However I am having problems changing the
code to fit my cell criteria/range. I've played around with this one
for quite some time, and the places that I would normally make changes
to the range doesn't seem to work.

Instead of A:A to B:B. .....I need this code to reflect B12:B3000 to
L12:L3000


Thanx.


Reposting code:

Private Sub Worksheet_Change(ByVal Target As Range)
Dim myRow As Long
If Target.Cells.Count 1 Then Exit Sub
If Target.Column < 1 Then Exit Sub


Application.EnableEvents = False
If Application.CountIf(Range("B:B"), Target.Value) = 0 Then
Range("B65536").End(xlUp)(2).Value = Target.Value
End If


For myRow = Range("B65536").End(xlUp).Row To 2 Step -1
If IsError(Application.Match(Cells(myRow, 2).Value, Range("A:A"),
False)) Then
Cells(myRow, 2).ClearContents
End If

Next myRow


Application.EnableEvents = True

End Sub