Need Visual Basic Help

[KC1AJT]

I am in the process of designing a scouting program.
I have the following code:
Private Sub teamnum_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles teamnum.KeyPress

Dim allowedChars As String = "0123456789"

If allowedChars.IndexOf(e.KeyChar) = -1 Then
' Invalid Character
e.Handled = True
End If

End Sub

But I would like to add the function of a backspace key.