how to add 'select ' to a Combo box item which has binded with a data table

private void BindCombo()

        {

            DataTable dataTable = GetDataTable();

            DataRow row = dataTable.NewRow();

            row["Code"] = "None";

            row["Name"] = "None";

            dataTable.Rows.InsertAt(row, 0);

            comboBox1.DisplayMember = "Name";

            comboBox1.ValueMember = "Code";

           

            comboBox1.DataSource = dataTable;

          

 

        }