function loadXMLDoc(dname) {
    var xmlDoc;
    if (window.XMLHttpRequest) {
        xmlDoc = new window.XMLHttpRequest();
        xmlDoc.open("GET", dname, false);
        xmlDoc.send("");
        return xmlDoc.responseXML;
    }
    // IE 5 and IE 6
    else if (ActiveXObject("Microsoft.XMLDOM")) {
        xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
        xmlDoc.async = false;
        xmlDoc.load(dname);
        return xmlDoc;
    }
    alert("Error loading document");
    return null;
}
function showNavigation() {

    xmlDoc = loadXMLDoc("xml/pclt-nav.xml");
    xslDoc = loadXMLDoc("xml/pclt-nav.xsl");
    if (window.ActiveXObject) {
        ex = xmlDoc.transformNode(xslDoc);
        document.getElementById("left-nav").innerHTML = ex;
    }
    // code for Mozilla, Firefox, Opera, etc.
    else if (document.implementation
                    && document.implementation.createDocument) {
        xsltProcessor = new XSLTProcessor();
        xsltProcessor.importStylesheet(xslDoc);
        resultDocument = xsltProcessor.transformToFragment(xmlDoc, document);
        document.getElementById("left-nav").appendChild(resultDocument);
    }
}