R help - Sep 2004 - How to plot residuals vs. fitted of "trgls" object (spatial::surf.gls)

Hi!

Would like to to make a plot of residuals vs. fitted and Y vs. predicted values 
from an object of class "trgls" as returned by spatial::surf.gls
directly.
(without calling spatial::predict.trgls)
Is it possible? on which list components should I look at?

/E