R help - Jan 2007 - arima.sim with a periodic model

Hi all.

I have a periodiv arma model and I want to simulate it. In S-plus, the 
following works for me:

phi <- 0.9
theta <- 0
p <- 1 # period
model <- list(ar=phi, ma=theta, period=p)
Yt <- arima.sim(model, n=250)

How do I do something like this "period=12" in R? I read
help(arima.sim)
but it doesn't tell.


Thanks! Philip.