Add a node with attributes using xpath and java

[konstantina]

Hello all,
I'm trying to insert a new node using xpath.
This is easy to do, but when i'm trying to add attributes to that node I get an exception. Here is my code:

reservationExpression = xpath.compile("/hotels/hotel/room[@id='" + roomId + "']");

        Node room = (Node) reservationExpression.evaluate(doc, XPathConstants.NODE);
        Node reservation =(Node) doc.createElement("reservation");

        Attr toDateAttr = doc.createAttribute("toDate");
        toDateAttr.setNodeValue(toDate);

        Attr fromDateAttr = doc.createAttribute("fromDate");
        fromDateAttr.setNodeValue(fromDate);

        Attr idAttr = doc.createAttribute("id");
        idAttr.setNodeValue("123");

        reservation.appendChild(toDateAttr);
        reservation.appendChild(fromDateAttr);
        reservation.appendChild(idAttr);

        room.appendChild(reservation);

        Source source = new DOMSource(doc);
        Result result = new StreamResult(filePath);
        Transformer transformer = TransformerFactory.newInstance().newTransformer();

        transformer.transform(source, result);

The exception that I get is the following:

java.lang.ClassCastException: com.sun.org.apache.xerces.internal.dom.ElementImpl cannot be cast to org.jdom.Element

I'm guessing this is not the right way to add an attribute to a node?
Any ideas would be appreciated!!

Thanks!!