protected void btnDelete_Click(object sender, EventArgs e)
 {
     var donation = Donation;
     donation.TotalQuantity = _donationDetailsManager.FetchAll(Donation.Id).Sum(dd => dd.Quantity)-DonationDetail.Quantity;
     _donationManager.Save(donation);
     txtTotalQuantity.Text = donation.TotalQuantity.ToString();
     var donationDetailToDelete = new DonationDetail
     {
         Id = DonationDetailId
     };
     _donationDetailsManager.Delete(donationDetailToDelete);
     divMessageBox.Visible = true;
     divMessageBox.Attributes.Add("class", "notify warning");
     ltrlMessageHeader.Text = "Saved Sucessful!";
     ltrlMessage.Text = "Donation Detail Entry has been deleted!";
     btnDelete.Enabled = false;
     btnSave.Enabled = false;
 }
        protected void btnSave_Click(object sender, EventArgs e)
        {
            var donationDetail = new DonationDetail
            {
                Barcode = txtBarcode.Text,
                DonationId = Donation.Id,
                Id = DonationDetailId,
                ItemId = int.Parse(DDLItems.SelectedValue),
                Price = decimal.Parse(txtPrice.Text),
                Quantity = int.Parse(txtItemQuantity.Text),
                Uid = Guid.NewGuid(),
                UnitId = int.Parse(DDLUnits.SelectedValue)
            };

            _donationDetailsManager.Save(donationDetail);
            var donation = Donation;
            donation.TotalQuantity = _donationDetailsManager.FetchAll(Donation.Id).Sum(dd=>dd.Quantity);
            _donationManager.Save(donation);
            txtTotalQuantity.Text = donation.TotalQuantity.ToString();
            divMessageBox.Visible = true;
            divMessageBox.Attributes.Add("class", "notify info");
            ltrlMessageHeader.Text = "Saved Sucessful!";
            ltrlMessage.Text = "Donation Detail Entry has been saved!";
        }