protected void Page_Load(object sender, EventArgs e) { GiftCertificate objgft = new GiftCertificate(); string message = "initialised"; try{ string couponcode = Request.QueryString["couponcode"]; string action = Request.QueryString["action"]; switch (action) { case ("checks"): message = objgft.Giftcodecheck(couponcode); break; case ("usecoupon"): int cartid = int.Parse(Request.QueryString["cartid"]); message = objgft.UseGiftcode(couponcode, cartid); break; default: message = "There is no such actions"; break; } } catch(Exception couponex) { message = couponex.Message; } Response.Write(message); }