Couple of E_NOTICE errors when theming the output.

I got a couple of E_NOTICE errors while testing the module some more (at the time I save a node to be exact.)

Somehow the settings do not always include the 'node' and 'syntax' parameters and when that happens, I get corresponding E_NOTICE errors.

I provide a patch (see attached.)

The 'node' parameter could further be checked to make sure it is a numeric identifier instead of just defined.

Thank you.
Alexis Wilke