private void LoadPayment(string paymentNo) { PaymentHeader pay = paymentProvider.GetPayment(paymentNo); IEnumerable <PaymentDetailViewModel> paymentDetail = null; if (pay != null) { lblPaymentNo.Text = pay.PaymentNo; lblPaymentDate.Text = pay.Date.ToString("dddd, dd MMMM yyyy"); lblStatusPayment.Text = pay.VoidDate.HasValue ? "Void" : "Active"; paymentDetail = paymentProvider.GetDetail(pay.InvoiceHeader.InvoiceNo); lblTotalPayment.Text = (paymentDetail.Any() ? paymentDetail.Sum(payment => payment.Amount) : 0).ToString("###,##0.00"); gvwPayment.DataSource = paymentDetail; gvwPayment.DataBind(); } }