Vertical text in a plot

Hi,

Consider this simple plot:

plot(1:25,runif(25,0,1),ylab="First Y-axis label",xaxt="n")

I want to add an additional axis as

axis(4,at=seq(0.2,1,.2), labels=1:5)

I have no idea how to add now the title of the new axis as "Second
Y-axis label". I want this text to be vertically directed from bottom
to top. I can't find the function in text() to write vertically. Any
ideas?

Thanks,
Marcin