///CREATE METHODS
        /// <summary>
        /// Creates a tariff object with the specifed attributes.  TariffBand objects must be created seperately using emAPI.createTariffBand.
        /// </summary>
        /// <param name="standingChargeValue">Value in £</param>
        /// <param name="startDate">shortdate string</param>
        /// <param name="standingChargePeriodId">id of Period for standing charge value (eg monthly, annually etc)</param>
        /// <param name="bandingPeriodId">id of Period for banding (currently unused)</param>
        /// <param name="meterId">id of meter to which tariff belongs</param>
        /// <returns>JSON representation of id of created tariff - int, wrapped in EMResponse</returns>
        public string createTariff(double standingChargeValue, string startDate, int standingChargePeriodId, int bandingPeriodId, int meterId)
        {
            EMResponse response = new EMResponse();
            try
            {
                tariffMgr = new TariffManager();
                response.data = EMConverter.fromObjectToJSON(tariffMgr.createTariff(standingChargeValue, startDate, standingChargePeriodId, bandingPeriodId, meterId));
                response.status = ok;
            }
            catch (Exception e)
            {
                response.status = error;
                response.data = e.Message;
            }

            return EMConverter.fromObjectToJSON(response);
        }