textbox accept number and backspace only

 textbox_KeyPressevent...

Dim number_backspace As String = "0123456789"
        If e.KeyChar <> ControlChars.Back Then
            If number_backspace.IndexOf(e.KeyChar) = -1 Then
                e.Handled = True
                MessageBox.Show("Enter only Number")
            Else
                e.Handled = False


            End If
        End If