处理Asp.net Ajax框架12029,12007错误

< asp:ScriptManager ID = " ScriptManager1 "  runat = " server " >
         </ asp:ScriptManager >

         < script language = " javascript "  type = " text/javascript " >
    Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler); 
     function  EndRequestHandler(sender, args)
     {
        
        if (args.get_error() != undefined)
        {
           if ((args.get_response().get_statusCode() == '12007') || (args.get_response().get_statusCode() == '12029'))
           {
                   
                   
                   document.writeln("服务器连接失败。");
                   window.onerror = false; //JS中遇到脚本错误时不做任何操作

            }
        }
    }
         </ script >