* Query the {@code nsIDOMHTMLFormElement} interface from the node.
* @param node the node to convert.
* @exception XPCOMException if the node is not a form.
*/
public static nsIDOMHTMLFormElement asForm(nsIDOMNode node) {
nsIDOMHTMLFormElement form = (nsIDOMHTMLFormElement) node.queryInterface(nsIDOMHTMLFormElement.NS_IDOMHTMLFORMELEMENT_IID);
return form;
}