net cookie操作

写入方法：
       HttpCookie cookie = new HttpCookie("id");
       cookie.Value=cookieValue;
       cookie.Expires = DateTime.Now+new TimeSpan(0,1,0,0));
       Response.Cookies.Add(cookie);
读取方法：
HttpCookie cookie = Request.Cookies["id"];             
              if(null == cookie)
              {
                   Label1.Text = "";
              }
              else
              {
                   Label1.Text = cookie.Value;
              }