[R] several plots in one

[JeeBee]

Can anyone tell me how I can supply more than one graph to plotCI
(gplots) at once?

Below is what I tried, also with rbind instead of cbind.
What is the way to do this (in general, I think)?

Problem is that lines of 1-st and 2-nd series are mixed, while they have
nothing to do with each other.

I also tried calling plotCI with argument add=TRUE, which didn't seem to
work (that is actually what I wanted I think).
(It should look the same as if I called plotCI twice with same
labels/xlim/ylim/etc.)

  plotCI(x = cbind(x1,x2),
         y = cbind(means1,means2), # means1 == ci1["Estimate",]
         xlim = c(0,100), #ylim = c(0.2,0.5),
         ylab = "System welfare", 
         pch = 7, col = c("red","blue"), type = "b",
         uiw = cbind(uiw1,uiw2))

Thanks in advance,
JeeBee.