?plot problem

Thanks to Dr. Thomas Hotz, Prof. Brian Ripley, Dr. Dennis
Murphy, and Dr. David Scott for their replies.

Trying an idea:

x <- c(1,2,3,4)
y<-c(2,4.2,5.9,9)
temp<-data.frame(cbind(x,y))
attach(temp)
temp.lm <- lm(y~x)
windows()
plot(temp.lm)

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dev.off()
windows()

I was unable to see the Cook's distance plot as before (using
the Page Up and Page Down keys).  So I implemented another
suggestion:

windows()
plot(temp.lm)

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[Use Menu: History|Add]

After doing this, the Cook's distance plot was "saved" so that
Page Up and Page Down worked properly.  Question:  Is there
a way to use a line command to "add" the last graph to the
history?