public ActionResult GetAllFreeProducts(int companyId)
        {
            string cmpny = Session["CompanyId"].ToString();
            var dbfactory = new DatabaseFactory();
            ChartOfProductService _ChartOfProductService = new ChartOfProductService(new ChartOfProductRepository(dbfactory), new UnitOfWork(dbfactory));
            var productlist = _ChartOfProductService.GetProducts(int.Parse(cmpny));

            var list = _FreeProductService.GetAll(int.Parse(cmpny)).ToList();

            List<SlsProduct> records = new List<SlsProduct>();
            foreach (SlsFreeProductsViewModel record in list)
            {
                var rec = productlist.Where(t => t.Id == record.SlsProductId).FirstOrDefault();
                if (rec != null)
                {
                    var isExist = records.Where(t => t.Id == rec.Id).FirstOrDefault();
                    if (isExist == null)
                    {
                        records.Add(rec);
                    }
                }
            }

            return Json(records, JsonRequestBehavior.AllowGet);
        }