MVC4用户关闭浏览器后更新用户登录状态

前台代码&＃xff1a;

　　function RunOnBeforeUnload() {
                //更改用户登录状态
                var currUser &＃61; getCOOKIE("UserAccount");
                $.ajax({
                    type: "post",
                    url: "../Home/UpdateLoginState",
                    data: { &＃39;currUser&＃39;: currUser},
                    dataType: "text",
                    async: false,
                    success: function (data) {
                        
                    }
                });
            }

后台代码&＃xff1a;

　　　//关闭浏览器后更改用户登录状态
        public ActionResult UpdateLoginState()
        {
            string currUser &＃61; "";
            string stateStr &＃61; "";
            if (Request["currUser"]!&＃61;null)
            {
                currUser &＃61; Request["currUser"].ToString();
                string updaStr &＃61; "update Users set OnLine&＃61;0 where UserAccount&＃61;&＃39;"&＃43;currUser.Trim()&＃43;"&＃39;";
                int coun &＃61; SqlHelper.ExecuteSql(updaStr);
                if (coun > 0)
                {
                    stateStr &＃61; "更改成功&＃xff01;";
                }
                else
                {
                    stateStr &＃61; "更改失败&＃xff01;";
                }
            }
            return Content(stateStr);
        }