private StringBuilder PopulateFeePendingDataInStringBuilder()
        {
            var stringBuilder = new StringBuilder();

            stringBuilder.Append(DoubleQuote + "Student Name" + DoubleQuoteAndComa);
            stringBuilder.Append(DoubleQuote + "Class Name" + DoubleQuoteAndComa);
            stringBuilder.Append(DoubleQuote + "Section Name" + DoubleQuoteAndComa);
            stringBuilder.Append(DoubleQuote + "Medium Name" + DoubleQuoteAndComa);
            stringBuilder.Append(DoubleQuote + "Academic Year" + DoubleQuoteAndComa);
            stringBuilder.Append(DoubleQuote + "Fee Paid" + DoubleQuoteAndComa);
            stringBuilder.Append(DoubleQuote + "Fee Due" + DoubleQuoteAndComa);
            stringBuilder.AppendLine();

            var accounts   = PageDataService.GetFeePendingDetailsByMediumIdByClassIdAdoNet(Convert.ToInt32(ddlMediumForGridView.SelectedValue), Convert.ToInt32(ddlClassForGridView.SelectedValue));
            var feeDetails =
                PageDataService.GetCurrentYearFeeMasterByMediumIdAndClassIdAdoNet(
                    Convert.ToInt32(ddlMediumForGridView.SelectedValue),
                    Convert.ToInt32(ddlClassForGridView.SelectedValue));
            var currentAcademicYear = PageDataService.GetActiveAcademicYearAdoNet();

            foreach (var account in accounts)
            {
                var scholarShipDetailsOfCurrentYear =
                    PageDataService.GetScholarShipDetailsByStudentIdAndAcademicYearIdAdoNet(account.Student.StudentId,
                                                                                            currentAcademicYear.
                                                                                            AcademicYearId);
                var scholarShipToatlAmountSanctioned = scholarShipDetailsOfCurrentYear.Aggregate(0,
                                                                                                 (current, scholarShipDetail)
                                                                                                 =>
                                                                                                 current +
                                                                                                 Convert.ToInt32(
                                                                                                     scholarShipDetail.
                                                                                                     AmountSanctioned));
                var feePending = Convert.ToInt32(feeDetails.Fee) - Convert.ToInt32(account.FeePaid) - Convert.ToInt32(account.CarryFarwordFee) - Convert.ToInt32(scholarShipToatlAmountSanctioned);
                if (feePending > 0)
                {
                    stringBuilder.Append(DoubleQuote + account.Student.StudentName + DoubleQuoteAndComa);
                    stringBuilder.Append(DoubleQuote + account.Class.ClassName + DoubleQuoteAndComa);
                    stringBuilder.Append(DoubleQuote + account.Student.Section.SectionName + DoubleQuoteAndComa);
                    stringBuilder.Append(DoubleQuote + account.Medium.MediumName + DoubleQuoteAndComa);
                    stringBuilder.Append(DoubleQuote + account.AcademicYear.AcademicYearStart + "-" + account.AcademicYear.AcademicYearEnd + DoubleQuoteAndComa);
                    stringBuilder.Append(DoubleQuote + Convert.ToInt32(account.FeePaid) + DoubleQuoteAndComa);
                    stringBuilder.Append(DoubleQuote + feePending + DoubleQuoteAndComa);
                    stringBuilder.AppendLine();
                }
            }

            return(stringBuilder);
        }