var MYAPP = MYAPP || {
                ajax : function(url, callback, method, data, async){
                    var method = method || 'GET',
                    async =  typeof(async) === 'boolean' ? async : true;
                    xmlHttp = null;

                    if (window.XMLHttpRequest) {
                        xmlHttp = new XMLHttpRequest();
                    } else if (window.ActiveXObject) {
                        try {
                            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
                        } catch(e) {
                            try {
                                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
                            } catch(e) {
                                xmlHttp = null;
                            }
                        }
                    } else if (window.createRequest) {
                        try {
                            xmlHttp = window.createRequest();
                        } catch (e) {
                            xmlHttp = null
                        }
                    };

                    if(xmlHttp){
                        xmlHttp.open(method, url, async);
                        xmlHttp.onreadystatechange = function() {
                            if (this.readyState === 4 && callback) {
                                if(this.status === 200) {
                                    callback(this.responseText);
                                    //console.log(this.getAllResponseHeaders());
                                }
                            }
                        };
                        if(method === 'POST'){
                            xmlHttp.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
                            xmlHttp.setRequestHeader('Content-length', data.length);
                            xmlHttp.setRequestHeader('Connection', 'close');
                        }
                        xmlHttp.send(data);
                    }
                },
                sendAjax : function(){
                    var obj1 = {id: '1', value: 'value-1'},
                    obj2 = {id: '2', value: 'value-2'},
                    url = '/home/ajax?data=client',
                    data = 'data=' + encodeURIComponent(JSON.stringify([obj1, obj2])),
                    obj = document.getElementById('result');

                    MYAPP.ajax(url, function(data){
                        obj.innerHTML += data;
                    }, 'POST', data);

                    MYAPP.ajax(url, function(data){
                        obj.innerHTML += '< br />' + data;
                    });

                    MYAPP.ajax(url);
                }
            };

var http = {};        
        http._factories = [
            function() { return new XMLHttpRequest(); },
            function() { return new ActiveXObject("Msxml2.XMLHTTP"); },
            function() { return new ActiveXObject("Microsoft.XMLHTTP"); }
        ];
        http._factory = null;
        http.newRequest = function () {
            if (http._factory != null) return http._factory();
            for (var i = 0; i < http._factories.length ; i++) {
                try {
                    var factory = http._factories[i];
                    var request = factory();
                    if (request != null) {
                        http._factory = factory;
                        return request;
                    }
                }
                catch (e) {
                    continue;
                }
            }
            http._factory = function () {
                throw new Error("Ky");
            };
            http._factory();
        };

namespace Simple
open System.Net
open System.Xml
open System.Xml.Linq
module HttpListener =    
    type msg =
    | Incr of string
    | Fetch of AsyncReplyChannel<string>

    let run (url:string,handler: (HttpListenerRequest -> HttpListenerResponse -> Async<unit>)) = 
        let listener = new HttpListener()
        listener.Prefixes.Add url
        listener.Start()
        let asynctask = Async.FromBeginEnd(listener.BeginGetContext,listener.EndGetContext)
        async {
            while true do 
                let! context = asynctask
                Async.Start (handler context.Request context.Response)
        } |> Async.Start 
        listener
    
    let counter =
        MailboxProcessor.Start(fun inbox ->
            let rec loop p =
                async { let! msg = inbox.Receive()
                        match msg with
                        | Incr(x) -> return! loop(p + x)
                        | Fetch(replyChannel) ->
                            replyChannel.Reply(p)
                            return! loop(p) }
            loop "\n")

    let up = run("http://*:80/Chat/", (fun req resp -> 
            async { // post format: http://server:80/Chat/it?post=message 
                let post = try req.QueryString.GetValues("post") |> Array.min with e -> "no comment\n"
                counter.Post(Incr (sprintf "<div class='chatroom'>%s</div>" post))
                let str = counter.PostAndReply(fun replyChannel -> Fetch replyChannel)
                let out = System.Text.Encoding.ASCII.GetBytes (sprintf "<div class='chatroom'>%s</div>" str)
                resp.OutputStream.Write(out,0,out.Length)
                resp.OutputStream.Close()
            }
        )) 

    up |> fun server -> printf "server.IsListening: %b\n" server.IsListening
    System.Console.Read () |> ignore

// Controller
        [HttpPost]
        [NoCache]
        public int AddMessage(ChatForm frm)
        {
            if (string.IsNullOrEmpty(frm.ChatMessage) || !CurrSession.IsValidChat)
                return 0;

            string NickName = CurrSession.Nickname;
            int TypeID = 0;
            int CustomerID = 0;

            if (CurrSession.IsValidCustomer)
            {
                NickName = CurrSession.CustomerUserName;
                CustomerID = CurrSession.CustomerID;
                TypeID = 1;
            }

            cRep.AddMessage(frm.ChatMemberID, NickName, frm.ChatMessage, TypeID, CustomerID);

            return 1;
        }

        [NoCache]
        public ActionResult List(int mID)
        {
            if (!CurrSession.IsValidChat)
                return Content("");

            var data = new ChatMessagesView
            {
                MemberID = mID,
                SmilesList = cRep.GetSmiles(),
                MessagesList = cRep.GetChatMessages(mID, 30, CurrSession.ChatStartTime)
            };
            return PartialView("_Messages", data);
        }

// Service
public void AddMessage(int MemberID, string Nickname, string Message, int TypeID, int CustomerID)
        {
            var m = new tblChatMessage();
            m.MemberID = MemberID;
            m.Nickname = Nickname;
            m.Message = Message;
            m.PostDate = DateTime.Now;
            m.TypeID = TypeID;
            m.CustomerID = CustomerID;

            db.AddTotblChatMessages(m);
            db.SaveChanges();
        }

        public IEnumerable<ChatMessage> GetChatMessages(int MemberID, int Num, DateTime StartDate)
        {
            return (from t in db.tblChatMessages
                    where t.MemberID == MemberID && t.PostDate >= StartDate
                    orderby t.MessageID descending
                    select new ChatMessage
                    {
                        Nickname = t.Nickname,
                        Message = t.Message,
                        TypeID = t.TypeID
                    }).Take(Num);
        }

// View
@model ChatMessagesView

@foreach (var m in Model.MessagesList)
{
    <div class="@Model.MessageCss(m.TypeID)">
      @m.Nickname: @Model.SetMessage(m.Message)
    </div>
}

$('a.ChatSendBtn').click(function ()
        {
            if (!$('#ChatMessage').val())
                return;

            var data = $('#ChatForm').serialize();
            $('#ChatMessage').val('');
            var ChatMemberID = $('#ChatMemberID').val();
            $.post("/chatbox/addmessage", data, function (val)
            {
                ShowChatMessages(ChatMemberID);
            });
        });


function ShowChatMessages(ChatMemberID)
{
    $.get("/chatbox/list?mID=" + ChatMemberID, function (data)
    {
        $('#ChatMsgList').html(data);
    });
}

// Client
$('a.ChatSendBtn').click(function ()
        {
            if (!$('#ChatMessage').val())
                return;

            var data = $('#ChatForm').serialize();
            $('#ChatMessage').val('');
            var ChatMemberID = $('#ChatMemberID').val();
            $.post("/chatbox/addmessage", data, function (val)
            {
                ShowChatMessages(ChatMemberID);
            });
        });


function ShowChatMessages(ChatMemberID)
{
    $.get("/chatbox/list?mID=" + ChatMemberID, function (data)
    {
        $('#ChatMsgList').html(data);
    });
}