public ActionResult Capnhapsoluong(string a, string a1)
        {
            List <GiohangModel> lg  = (List <GiohangModel>)Session["giohang"];
            GiohangModel        obj = new GiohangModel();

            if (!TestSo(a))
            {
            }
            else
            {
                obj = lg.Where(e => e.Productid == Convert.ToInt32(a1)).FirstOrDefault();
                GiohangModel g = new GiohangModel();
                g.Productid   = Convert.ToInt32(a1);
                g.ProductName = obj.ProductName;
                g.Quality     = obj.Quality;
                g.Descript    = obj.Descript;
                g.Soluong     = Convert.ToInt32(a);
                lg.RemoveAll(x => x.Productid == Convert.ToInt32(a1));

                lg.Insert(0, g);
                Session["giohang"] = lg;
                Response.Write("ok");
            }
            return(null);
        }
        private void updatequality(int id)
        {
            List <GiohangModel> ls = (List <GiohangModel>)Session["giohang"];
            GiohangModel        gm = new GiohangModel();

            gm = ls.Where(g => g.Productid == id).FirstOrDefault();
            GiohangModel gm1 = new GiohangModel();

            gm1.Productid   = id;
            gm1.ProductName = gm.ProductName;
            gm1.Quality     = gm.Quality;
            gm1.Soluong     = gm.Soluong + 1;
            ls.RemoveAll(x => x.Productid == id);
            //ls.Add(gm1);
            ls.Insert(0, gm1);
            Session["giohang"] = ls;
        }
        public ActionResult giohang(int id)
        {
            string            a  = "";
            StationeryModelcs sc = new StationeryModelcs();

            if (Session["giohang"] == null)
            {
                List <GiohangModel> lg1 = new List <GiohangModel>();
                GiohangModel        gl  = new GiohangModel();
                gl.ProductName = sc.stati(id).ProductName;
                gl.Productid   = sc.stati(id).ProductId;
                gl.Quality     = Convert.ToInt32(sc.stati(id).Quantity);
                gl.Descript    = sc.stati(id).Description;
                gl.Soluong     = 1;
                lg1.Add(gl);
                Session["giohang"] = lg1;

                a += "<tr class='remove' >";
                a += String.Format("<td class='id'>{0}</td>", gl.Productid);
                a += String.Format("<td>{0}</td>", gl.ProductName);
                a += String.Format("<td>{0}</td>", gl.Quality);
                a += String.Format("<td>{0}</td>", gl.Descript);
                a += String.Format("<td><input type='type' name='sl' class='sl' value='{0}'  /></td>", gl.Soluong);
                a += String.Format("<td><button class='remove1'>Remove</button><input type='hidden' class='giatri1' value='{0}'></td></td>", gl.Productid);
                a += "</tr>";

                Response.Write(a);
            }
            else
            {
                if (TestProduct(id))
                {
                    string a1 = "";
                    updatequality(id);
                    List <GiohangModel> gh = (List <GiohangModel>)Session["giohang"];
                    foreach (GiohangModel g in gh)
                    {
                        a1 += "<tr class='remove'>";
                        a1 += String.Format("<td class='id'>{0}</td>", g.Productid);
                        a1 += String.Format("<td>{0}</td>", g.ProductName);

                        a1 += String.Format("<td>{0}</td>", g.Quality);
                        a1 += String.Format("<td>{0}</td>", g.Descript);
                        a1 += String.Format("<td><input type='type' name='sl' class='sl' value='{0}' /></td>", g.Soluong);
                        a1 += String.Format("<td><button class='remove1'>Remove</button><input type='hidden' class='giatri1' value='{0}'></td></td>", g.Productid);
                        a1 += "</tr>";
                    }
                    Response.Write(a1);
                }
                else
                {
                    List <GiohangModel> lg1 = (List <GiohangModel>)Session["giohang"];
                    Stationery          s1  = sc.stati(id);
                    GiohangModel        gm1 = new GiohangModel();
                    gm1.Productid   = s1.ProductId;
                    gm1.ProductName = s1.ProductName;
                    gm1.Quality     = Convert.ToInt32(s1.Quantity);
                    gm1.Soluong     = 1;
                    lg1.Insert(0, gm1);

                    Session["giohang"] = lg1;

                    string a2 = "";
                    foreach (GiohangModel g in (List <GiohangModel>)Session["giohang"])
                    {
                        a2 += "<tr class='remove'>";
                        a2 += String.Format("<td class='id'>{0}</td>", g.Productid);
                        a2 += String.Format("<td>{0}</td>", g.ProductName);

                        a2 += String.Format("<td>{0}</td>", g.Quality);
                        a2 += String.Format("<td>{0}</td>", g.Descript);
                        a2 += String.Format("<td><input type='type' name='sl' class='sl' value='{0}' /></td>", g.Soluong);
                        a2 += String.Format("<td><button class='remove1'>Remove</button><input type='hidden' class='giatri1' value='{0}'></td></td>", g.Productid);
                        a2 += "</tr>";
                    }
                    Response.Write(a2);
                }
            }
            return(null);
        }