Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
On Error GoTo Son
If Intersect(Target, [B2:K65536]) Is Nothing Then Exit Sub
If Target <> "" Then
If WorksheetFunction.CountIf(Range(Cells(Target.Row, "B"), Cells(Target.Row, "K")), Target) > 1 Then
MsgBox "Bu kayıt daha önce girilmiştir !", vbCritical, "Mükerrer Kayıt !"
Target.ClearContents
Exit Sub
End If
End If
Son:
End Sub