public void SaveItemMasterDetails(Billing_Item billingItem)
        {
            BillingDbContextBll db = new BillingDbContextBll();

            if (billingItem.ItemID == 0)
            {
                db.Entry(billingItem).State = System.Data.Entity.EntityState.Added;
            }
            else
            {
                db.Entry(billingItem).State = System.Data.Entity.EntityState.Modified;
            }
            db.SaveChanges();
        }
        public void DeleteBillItemDetailsBasedOnId(int itemId)
        {
            Billing_Item        billingItem = new Billing_Item();
            BillingDbContextBll db          = new BillingDbContextBll();

            billingItem = db.BillingItem.FirstOrDefault(a => a.ItemID == itemId);
            db.Entry(billingItem).State = System.Data.Entity.EntityState.Deleted;
            db.SaveChanges();
        }