Highlight all the occurances when we click or highlight one cell

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Static sOldRng As Range
Dim r As Range

If Target.Cells.Count > 1 Then Exit Sub
If Target.Value = "" Then Exit Sub

If Not sOldRng Is Nothing Then
    With sOldRng
        .Font.ColorIndex = xlColorIndexAutomatic
        .Interior.ColorIndex = xlColorIndexNone
    End With
    Set sOldRng = Nothing
End If

For Each r In ActiveSheet.UsedRange
    If r.Value = Target.Value Then
        If sOldRng Is Nothing Then
        Set sOldRng = r
        Else
        Set sOldRng = Union(sOldRng, r)
        End If
    End If
Next r

With sOldRng
    .Font.Color = vbRed
    .Interior.Color = vbYellow
End With

End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Cells.Count = 1 Then
With UsedRange
  .FormatConditions.Delete
  .FormatConditions.Add Type:=xlCellValue, Operator:=xlEqual, Formula1:="=" & Target.Address
  .FormatConditions(1).Interior.ColorIndex = 7
End With
End If
End Sub