private void comboBox4_SelectedIndexChanged(object sender, EventArgs e)
    {
        renameOld = comboBox4.Text;
        var names = renameOld.Split(new[] { ", " }, System.StringSplitOptions.RemoveEmptyEntries);
        foreach (string items in names)
        {
            Console.WriteLine(items);
        }

    }

renameOld = "Johnson, James"