function xpath()
{
    var numHeadings;
    var resultNode = document.getElementById("result");
    var headings = document.evaluate("//h1", document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);

    if(headings.snapshotLength)
        numHeadings = headings.snapshotLength;
    else
        numHeadings = 0;

    var result = document.createTextNode(numHeadings);
    resultNode.appendChild(result);

    return false;
}