ADPAPIClient.Case.toJson C# (CSharp) Method

        public string toJson()
        {
            Dictionary<string, string> myDict = new Dictionary<string, string>();

            // mandatory fields
            myDict.Add("api_key", this.apiKey);
            myDict.Add("creator_email", this.creatorEmail);
            myDict.Add("advocate_email", this.advocateEmail);
            myDict.Add("case_number", this.caseNumber);
            myDict.Add("case_type_id", this.caseType);
            myDict.Add("court_id", this.courtId);
            myDict.Add("offence_id", "36");

            myDict.Add("first_day_of_trial", convertDate(this.trialStartDate));
            myDict.Add("estimated_trial_length", Convert.ToString(this.estimatedTrialLength));
            myDict.Add("actual_trial_length", Convert.ToString(this.actualTrialLength));
            myDict.Add("trial_concluded_at", convertDate(this.endTrialDate));
            myDict.Add("advocate_category", this.advocateCategory);

            // optional fields
            // - only send them if they have a value
            if (!String.IsNullOrEmpty(this.cmsNumber))              myDict.Add("cms_number", this.cmsNumber);
            if (!String.IsNullOrEmpty(this.additionalInformation))  myDict.Add("additional_information", this.additionalInformation);
            if (!String.IsNullOrEmpty(this.applyVat.ToString()))    myDict.Add("apply_vat", Convert.ToString(this.applyVat));

            if (this.trialFixedNoticeAt != new DateTime())          myDict.Add("trial_fixed_notice_at", convertDate(this.trialFixedNoticeAt));
            if (this.trialFixedAt != new DateTime())                myDict.Add("trial_fixed_at", convertDate(this.trialFixedAt));
            if(this.trialCrackedAt != new DateTime())               myDict.Add("trial_cracked_at", convertDate(this.trialCrackedAt));
            if (!String.IsNullOrEmpty(this.trialCrackedAtThird))    myDict.Add("trial_cracked_at_third", this.trialCrackedAtThird);

            //don't think the IsoDateTimeConverter has any impact here
            return JsonConvert.SerializeObject(myDict, new IsoDateTimeConverter());
        }

        private void createCaseButton_Click(object sender, EventArgs e)
        {
            statusMessage.Text = postingClaimStatusMessage;
            Case       myCase  = populateCase();
            HttpClient client  = new HttpClient();
            string     payload = myCase.toJson();

            string response = client.createClaim(payload);

            sentToServerLabel.Text   = formatSentToServerLabel(client, payload);
            statusMessage.Text       = displayResponseStatusMessage;
            responseLabel.Text       = responseLabelText;
            serverResponseLabel.Text = "Status: " + client.responseStatusCode + "  " + response;
        }