Using panel.grid in barchart

I'm trying to do an example in Deepayan Sarkar's Lattice book.  It  
involves making a barchart based on the Titanic dataset.  I can get  
the barchart to plot fine; however, when I try to edit panel.grid, I  
get an error:

 > titan<-barchart(Class ~ Freq | Age + Sex, data =  

as.data.frame(Titanic), groups=Survived, stack=TRUE, layout=c(4,1),  
auto.key=list(title="Survived", columns=2), scales=list(x="free"))

 > titan     <--- this plot is fine
 > update(titan, panel = function(...) { panel.barchart(...)})  <--- 

same thing; also fine

 > update(titan, panel = function(...) { panel.grid(h = 0,v = -1)  

panel.barchart(...)})
Error: syntax error