5*会话取消

 protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                Response.Write("同时在线人数："+Application["online"]);
            }
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            Session.Abandon();//取消当前会话
            Response.Write("取消会话");
        }