internal CompraDB getCompraByPNR(string pnr)
        {
            CompraDB compras = null;

            try
            {
                //
                // Open the SqlConnection.
                //
                con.Open();
                //
                // The following code uses an SqlCommand based on the SqlConnection.
                //
                SqlCommand cmd = new SqlCommand(String.Format("SELECT TOP 1 [PNR],[Precio],[Fecha_Compra],[Viaje],[Forma_Pago],[Cliente]  FROM [GD2C2015].[JANADIAN_DATE].[Compra] where PNR={0} ", pnr), con);
                DataTable dt = new DataTable();

                dt.TableName = "Tabla";
                dt.Load(cmd.ExecuteReader());
                if (dt.Rows.Count == 0)
                {
                    con.Close();
                   return null;
                }
                foreach (DataRow Fila in dt.Rows)
                {
                    compras = new CompraDB(Convert.ToInt32(Fila["PNR"]), Convert.ToDouble(Fila["Precio"]), Convert.ToDateTime(Fila["Fecha_Compra"]), Convert.ToInt32(Fila["Viaje"]), Convert.ToString(Fila["Forma_Pago"]), Convert.ToInt32(Fila["Cliente"]));
                }
                con.Close();
            }
            catch (Exception exAlta)
            {
                con.Close();
                throw (new Exception(exAlta.ToString()));

            }
            return compras;
        }
        internal int insertarCompra(CompraDB compra)
        {
            int idCompra = 0;
            try
            {
                con.Open();
                SqlCommand insertCompra = new SqlCommand(String.Format("INSERT INTO [GD2C2015].[JANADIAN_DATE].[Compra] (Precio,Fecha_Compra,Viaje,Forma_Pago,Cliente) VALUES ({0:0.00},'{1}',{2},'{3}',{4})", compra.getPrecio.ToString().Replace(",", "."), compra.getFecha, compra.getViaje, compra.getFormaPago, compra.getCliente), con);
                insertCompra.ExecuteNonQuery();

                SqlCommand cmd = new SqlCommand(String.Format("SELECT SCOPE_IDENTITY() as Cont "), con);
                DataTable dt = new DataTable();

                dt.TableName = "Tabla";
                dt.Load(cmd.ExecuteReader());
                if (dt.Rows.Count == 0)
                {
                    con.Close();
                    new Exception();
                }
                foreach (DataRow Fila in dt.Rows)
                {
                    idCompra = Convert.ToInt32(Fila["Cont"]);
                    break;
                }

                con.Close();
            }
            catch (Exception exAlta)
            {
                con.Close();
                throw (new Exception(exAlta.ToString()));

            }

            return idCompra;
        }