[R] I have an xyplot, I want to keep the format, but only show x or y

[Porter,Phillip C]

Good Morning,
I am using xyplot to show two variables for a large number of 
subjects.

Currently I am using xyplot(y~x|as.factor(ID), layout=c(7,9)) to 
give me a little plot of the x and y factors for each ID.

The purpose of the plot is to let the PI quickly look through the 
data for irregularities.

The good news is that they like the layout of the xyplot, but they 
don't want to have to think in two directions at once.

xyplot(x|as.factor(ID), layout=c(7,9)) and xyplot(y|as.factor(ID), 
layout=c(7,9)) would be perfect, but that isn't what xyplot does.  
What function can I use to replicate the layout of the xyplot, but 
only show one variable per subject?

Thanks,
Phillip