*/
    public static boolean instanceOf(Object a, Object b, Context cx)
    {
        // Check RHS is an object
        if (! (b instanceof Scriptable)) {
            throw typeError0("msg.instanceof.not.object");
        }

        // for primitive values on LHS, return false
        // XXX we may want to change this so that
        // 5 instanceof Number == true
        if (! (a instanceof Scriptable))
            return false;

        return ((Scriptable)b).hasInstance((Scriptable)a);
    }