var AjaxFunction = new function() {
    this.pool = new Array();
    this.getXMLHttp = function (chunnel) {
        if (chunnel != null) {
            for (var a = 0; a < this.pool.length; a++) {
                if (this.pool[a]["chunnel"] == chunnel) {
                    if (this.pool[a]["obj"].readyState == 0 || this.pool[a]["obj"].readyState == 4) {
                        return this.pool[a]["obj"];
                    } else {
                        return "busy";
                    }
                }
            }
            this.pool[this.pool.length] = new Array();
            this.pool[this.pool.length - 1]["obj"] = this.createXMLHttp();
            this.pool[this.pool.length - 1]["chunnel"] = chunnel;
            return this.pool[this.pool.length - 1]["obj"];

        }
        for (var i = 0; i < this.pool.length; i++) {
            if (this.pool[i]["obj"].readyState == 0 || this.pool[i]["obj"].readyState == 4) {
                return this.pool[i]["obj"];
            }
        }

        this.pool[this.pool.length] = new Array();
        this.pool[this.pool.length - 1]["obj"] = this.createXMLHttp();
        this.pool[this.pool.length - 1]["chunnel"] = "";
        return this.pool[this.pool.length - 1]["obj"];
    }

    this.createXMLHttp = function () {
        if (window.XMLHttpRequest) {
            var xmlObj = new XMLHttpRequest();
        } else {
            var MSXML = ['Microsoft.XMLHTTP', 'MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP'];
            for (var n = 0; n < MSXML.length; n++) {
                try {
                    var xmlObj = new ActiveXObject(MSXML[n]);
                    break;
                } catch(e) {
                }
            }
        }
        return xmlObj;
    }

    this.doAction = function (url, data, callback, chunnel) {
        var objXMLHttp = this.getXMLHttp(chunnel)
        if (typeof(objXMLHttp) != "object") {
            return;
        }
        url += (url.indexOf("?") >= 0) ? "&nowtime=" + new Date().getTime() : "?nowtime=" + new Date().getTime();
        if (data == "") {
            objXMLHttp.open('GET', url, true);
            objXMLHttp.send('');
        } else {
            objXMLHttp.open('POST', url, true);
            objXMLHttp.setRequestHeader("Content-Length", data.length);
            objXMLHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
            objXMLHttp.send(data);
        }
        if (typeof(callback) == "function") {
            objXMLHttp.onreadystatechange = function () {
                if (objXMLHttp.readyState == 4) {
                    if (objXMLHttp.status == 200 || objXMLHttp.status == 304) {
                        callback(objXMLHttp)
                    } else {
                        //alert("¼ÓÔØURL³ö´í\n" + objXMLHttp.status + ":" + objXMLHttp.statusText);
                    }
                }
            }
        }
    }
}