// very simple version of $X
// $X(exp);
// $X(exp, context, resolver, XPathResult.NUMBER_TYPE).numberValue;
// @source https:/raw.github.com/gist/29681
function $X (exp, context, resolver, result_type) {
	context || (context = document);
	var Doc = context.ownerDocument || context;
	var result = Doc.evaluate(exp, context, resolver, result_type || XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
	if (result_type) return result;
	for (var i = 0, len = result.snapshotLength, res = new Array(len); i < len; i++) {
		res[i] = result.snapshotItem(i);
	}
	return res;
}