关于读取xml文件的问题

var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async = "false";
xmlDoc.validateOnParse = "true";
xmlDoc.load("xmlFile.xml");

document.write("<br/>Error Code:");
document.write(xmlDoc.parseError.errorCode);
document.write("<br/>Error Reason:");
document.write(xmlDoc.parseError.reason);
document.write("<br/>Error line:");
document.write(xmlDoc.parseError.line);

var oXmlDom = document.implementation.createDocument("", "", null);
oXmlDom.load("xmlFile.xml");
oXmlDom.onload = function () {
    if(oXmlDom.documentElement.tagName == "parsererror")
        alert(oXmlDom.documentElement.firstChild.nodeValue);
};