XL 2013 Marcro pour qu'une cellule soit vide lorsqu'il y un doublon

Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
For i = 1 To Target.Row-1
    If Range("A" & i) = Target Then
        MsgBox ("Deja saisi en ligne ") & i
        Target = ""
        exit for
   end if
Next i
Application.EnableEvents = True
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
If Target.Count > 1 Then Exit Sub
For i = 1 To Target.Row - 1
    If Range("A" & i) = Target Then
        MsgBox ("Deja saisi en ligne ") & i
        Target = ""
        Exit For
   End If
Next i
If Not Intersect(Target, Range("A:A")) Is Nothing Then
    If Target = "" Then
        Cells(Target.Row, 14 + Target.Column) = ""
    Else
        Cells(Target.Row, 14 + Target.Column) = Date
    End If
End If

Application.EnableEvents = True
End Sub