[atefkhalf2004]

Public Sub emptycolumn()
        For i As Integer = 0 To datagridview1.Rows.Count - 1
            For j = 6 To 9
                If IsDBNull(datagridview1.Rows(i).Cells(j).Value) Then
                    datagridview1.Rows(i).Cells(j).Value = "*"
                End If
            Next j
        Next i
        For i As Integer = 0 To datagridview1.Rows.Count - 1
            For j = 6 To 9
                If String.IsNullOrEmpty(datagridview1.Rows(i).Cells(j).Value) Then
                    datagridview1.Rows(i).Cells(j).Value = "*"
                End If
            Next j

        Next i


    End Sub

استخدم هذا الكود  لتعبئة اعمدة ب  *
وضعت هذا الكود في موديول لا ينفذ 
لماذا
ولا يظهر خطأ معين