public void campos(ComboBox box, string tabla)
        {
            sentencias      sc        = new sentencias();
            OdbcDataAdapter dCampos   = sc.ConsultarCampos(tabla);
            DataTable       datCampos = new DataTable();

            dCampos.Fill(datCampos);

            if (datCampos.Rows.Count > 0)
            {
                for (int i = 0; i < datCampos.Rows.Count; i++)
                {
                    DataRow rows = datCampos.Rows[i];
                    string  cam  = rows["Field"].ToString();
                    box.Items.Add(cam);
                }
            }
        }