public JsonResult Get_Product(string prefix)
        {
            DataSet ds = objbl.Bind_productdetail(prefix, "%");

            foreach (DataRow dr in ds.Tables[0].Rows)
            {
                purchase.Add(
                    new Purchase
                {
                    productName1 = Convert.ToString(dr["ProductName"]),
                    ProductID1   = Convert.ToString(dr["ProductID"]),
                });
            }
            return(new JsonResult {
                Data = purchase, JsonRequestBehavior = JsonRequestBehavior.AllowGet, MaxJsonLength = 86753090
            });
        }