Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column = 7 Then
roww = Target.Row
If Application.WorksheetFunction.CountIf(Range("g1:g" & roww), Target.Value) <> 1 Then
MsgBox "«½Æ§å¸¹"
Target.Interior.ColorIndex = Application.WorksheetFunction.RandBetween(1, 50)
Else
Exit Sub
End If
End If
End Sub