var zXml = {
useActiveX: (typeof ActiveXObject != "undefined"),
useXmlHttp: (typeof XMLHttpRequest != "undefined")
};

zXml.ARR_XMLHTTP_VERS = ["MSXML2.XmlHttp.6.0", "MSXML2.XmlHttp.3.0"];

function zXmlHttp() { }

zXmlHttp.createRequest = function () {
if (zXml.useXmlHttp) return new XMLHttpRequest();

if (zXml.useActiveX) //IE < 7.0 = use ActiveX
{
if (!zXml.XMLHTTP_VER) {
for (var i = 0; i < zXml.ARR_XMLHTTP_VERS.length; i++) {
try {
new ActiveXObject(zXml.ARR_XMLHTTP_VERS[i]);
zXml.XMLHTTP_VER = zXml.ARR_XMLHTTP_VERS[i];
break;
} catch (oError) { }
}
}
if (zXml.XMLHTTP_VER) return new ActiveXObject(zXml.XMLHTTP_VER);
}
alert("对不起，您的电脑不支持 XML 插件，请安装好或升级浏览器。");
};