VBA: Detection bord tableau

Dim oldtarget As Range 
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    Set champ = Range("A1:BZ" & Range("TableauDeBord").Rows.Count + 1) 
 If Not oldtarget Is Nothing Then oldtarget.EntireRow.Borders.LineStyle = xlNone
    If Not Intersect(Target, champ) Is Nothing Then
        If Target.Count = 1 Then
            With Target.EntireRow
                With .Borders(xlEdgeTop)
                    .Weight = xlMedium
                    .Color = RGB(255, 0, 0)
                End With
                    With .Borders(xlEdgeBottom)
                    .Weight = xlMedium
                    .Color = RGB(255, 0, 0)
                    End With
                End With
            End If
        End If
    Set oldtarget = Target 
End Sub