var Request = {

    inited: false,
    xmlHttp: null,
    callback: null,

    init: function () {
        if (window.ActiveXObject) {
            this.xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        else if (window.XMLHttpRequest) {
            this.xmlHttp = new XMLHttpRequest();
        }
        else {
            alert("对不起,您使用的浏览器不支持XmlHttpRequest。");
        }
    },

    ReadyStateChange: function () {
        if (this.xmlHttp.readyState == 4 && this.callback) {
            this.callback(this.xmlHttp.responseText);
        }
    },

    send: function (url, post, callback) {
        if (!this.inited) {
            this.init();
            this.inited = true;
        }

        this.callback = callback || null;
        this.xmlHttp.open("POST", url, true);
        this.xmlHttp.onreadystatechange = this.ReadyStateChange.bind(this);
        this.xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        this.xmlHttp.send(post);
    }
};