public IEnumerable<GeckoNode> GetNodes(string xpath)
{
nsIDOMXPathEvaluator evaluator = Xpcom.CreateInstance<nsIDOMXPathEvaluator>("@mozilla.org/dom/xpath-evaluator;1");
nsIDOMNode node = (nsIDOMNode)this.DomObject;
nsIDOMXPathNSResolver resolver = evaluator.CreateNSResolver(node);
nsIDOMXPathResult result = (nsIDOMXPathResult)evaluator.Evaluate(new nsAString(xpath), node, resolver, 0, null);
return new GeckoNodeEnumerable(result);
}