Ajax基本メソッド

//汎用XMLHttpRequestオブジェクト生成
function createHttpRequest()
        {
        //Win ie用
        if(window.ActiveXObject)
                {
                try {
                        //MSXML2以降用
                        return new ActiveXObject("Msxml2.XMLHTTP"); //[1]'
                        }
                catch (e) {
                                try {
                                //旧MSXML用
                                return new ActiveXObject("Microsoft.XMLHTTP"); /
/[1]'
                                        }
                                 catch (e2) {
                                return null;
                                        }
                                }
                }
        else if(window.XMLHttpRequest)
                {
                //Win ie以外のXMLHttpRequestオブジェクト実装ブラウザ用
                return new XMLHttpRequest(); //[1]'
                }
        else
                {
                return null;
                }
        }


//XML送受信実行メソッド
function requestFile( data , method , fileName , async)
        {
        //XMLHttpRequestオブジェクト生成
        var httpoj = createHttpRequest(); //[1]

        //open メソッド
        httpoj.open( method , fileName , async ); //[2]

        //リクエストヘッダ送信
        httpoj.setRequestHeader('Content-Type',"application/x-www-form-urlencode
d;charset=UTF-8");

        //受信時に起動するイベント
        httpoj.onreadystatechange = function()  //[4]
                {
                //readyState値は4で受信完了
                switch(httpoj.readyState)
                        {
                        case 0:
                                load_message('イベント取得中.....');
                                break;
                        case 1:
                                //コールバック
                                load_message('データ生成中.....');
                                break;
                        case 2:
                                load_message('データ送信中.....');
                                break;
                        case 3:
                                load_message('データ受信中.....');
                                break;
                        case 4:
                                //コールバック
                                on_loaded(httpoj);
                                break;
                        }
                }

        //send メソッド
        httpoj.send( data ) //[3]
        }


//XML受信完了時のコールバック関数
function on_loaded(oj)
        {

        //完了時メッセージ
        var mess = '';

        //レスポンスを取得
        res = oj.responseXML; //[6]

        //Textモードでも
        tres = oj.responseText;

        //winの場合XMLで無くても通ってしまうので
        if(res == null || !tres.match("(<|>)"))
                {
                //エラー
                }
        else
                {
                //ここにXML解析ロジック記述
                }
        }