js跨浏览器实现将字符串转化为xml对象的方法

function loadXML(xmlString) {
var xmlDoc = null;
if (!window.DOMParser && window.ActiveXObject) {
var xmlDomVersions = ['MSXML.2.DOMDocument.6.0', 'MSXML.2.DOMDocument.3.0', 'Microsoft.XMLDOM'];
for (var i = 0; i < xmlDomVersions.length; i++) {
try {
xmlDoc = new ActiveXObject(xmlDomVersions[i]);
xmlDoc.async = false;
xmlDoc.loadXML(xmlString);
break;
} catch (e) {
}
}
}
else if (window.DOMParser && document.implementation && document.implementation.createDocument) {
try {

domParser = new DOMParser();
xmlDoc = domParser.parseFromString(xmlString, 'text/xml');
} catch (e) {
}
}
else {
return null;
}

return xmlDoc;
}