function HTTPRequest()
{
    this.request    = null;
    this.response   = null;
    this.method     = 'POST';
    //this.open     = open;
    //this.send     = send;
    try {
        this.xmlhttp = new XMLHttpRequest();
    } catch (e) {
        var XMLHTTP_IDS = new Array(
            'MSXML2.XMLHTTP.5.0',
            'MSXML2.XMLHTTP.4.0',
            'MSXML2.XMLHTTP.3.0',
            'MSXML2.XMLHTTP',
            'Microsoft.XMLHTTP' );
        var success = false;
        for (var i=0;i < XMLHTTP_IDS.length && !success; i++) {
            try {
                this.xmlhttp = new ActiveXObject(XMLHTTP_IDS[i]);
                success = true;
                break;
            } catch (e) {}
        }
        if (!success) {
            throw new Error('Unable to create XMLHttpRequest.');
        }
    }
}

HTTPRequest.prototype.open = function (url)
{
    this.xmlhttp.open(this.method, url, false);
    this.xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=gbk');
}

HTTPRequest.prototype.send = function (queryString)
{
    this.request = queryString;
    this.xmlhttp.send(queryString);
    if(this.xmlhttp.readyState == 4 && this.xmlhttp.status == 200) {
        this.response = this.xmlhttp.responseText;
    }
}