[R] lattice: put key where unused panel would have been

[Benjamin Tyner]

Hi,

Say I have

z<-data.frame(y=runif(190),
                       x=runif(190),
                       f=gl(5,38),
                       g=gl(19,10))

plot<-xyplot(y~x|g,
                     data=z,
                     layout=c(5,4),
                     groups=f,
                     auto.key=TRUE)

How might one place the key in the empty space where the twentieth panel 
would have been?

Thanks,
Ben