参考：

1. http://api.jquery.com/ajaxError/
2. http://stackoverflow.com/questions/123726/401-response-code-for-json-requests-with-asp-net-mvc
3. http://stackoverflow.com/questions/377644/jquery-ajax-error-handling-show-custom-exception-messages
4. http://archive.cnblogs.com/a/1814714/
5. http://www.open-china.net/blog/87546.html
6. http://blog.bandao.cn/archive/28359/index.aspx?tags=filter
7. http://msdn.microsoft.com/zh-cn/library/h6bb9cz9(v=vs.80).aspx
8. http://blog.csdn.net/y_h_t/article/details/6086573
9. http://stackoverflow.com/questions/859309/session-end-in-asp-net-mvc
10. http://stackoverflow.com/questions/2373209/when-is-session-end-called-in-asp-net-mvc
11. http://hi.baidu.com/chen_claire/blog/item/c29cbbeedf2c2b1cfdfa3cf9.html

Jquery handleSuccess  handleError

方式名称
 存储方式
 性能
 
Off
 设置为不使用Session功能
 无
 
InProc
 设置为将Session存储在进程内，就是ASP中的存储方式，这是默认值。
 性能最高
 
StateServer
 设置为将Session存储在独立的状态服务中。通常是aspnet_state.exe进程.
 性能损失10-15%
 
SQLServer
 设置将Session存储在SQL Server中。
 性能损失10-20%
 
Customer
 自定制的存储方案
 由实现方式确定

 private const string AjaxTempKey = "__isAjax";
        public bool IsAjax { get { return Request.IsAjaxRequest() || (TempData.ContainsKey(AjaxTempKey)); } }
        protected override RedirectResult Redirect(string url)
        {
            ensureAjaxFlag();
            return base.Redirect(url);
        }
        protected override RedirectToRouteResult RedirectToAction(string actionName, string controllerName, System.Web.Routing.RouteValueDictionary routeValues)
        {
            ensureAjaxFlag();
            return base.RedirectToAction(actionName, controllerName, routeValues);
        }
        protected override RedirectToRouteResult RedirectToRoute(string routeName, System.Web.Routing.RouteValueDictionary routeValues)
        {
            ensureAjaxFlag();
            return base.RedirectToRoute(routeName, routeValues);
        }
        private void ensureAjaxFlag()
        {
            if (IsAjax)
                TempData[AjaxTempKey] = true;
            else if (TempData.ContainsKey(AjaxTempKey))
                TempData.Remove(AjaxTempKey);
        }

$(document).ready(function(){
    var currentUrl = (location.href).replace("http://", "");
    var currentUrlArr = currentUrl.split("/");
    var folderLen = currentUrlArr.length - 3;
    var urlRightStr = "";
        //这里用来处理getSessionValueAJAX.asp文件的相对路径
    for (var i = 0; i < folderLen; i++){
        urlRightStr += "../";
    }
    $.ajax({ 
            type:"POST",
            async:false,
            url:urlRightStr+"getSessionValueAJAX.asp?r="+getRandom(), 
            success: function(data){ 
                if (data == "out"){
                    window.parent.location = urlRightStr+"login.asp";
                }
            }
    });
   
});

<% if (session("login_name") = "" ) then
    response.Write("out")
  else
    response.Write("on")
  end if
%>