[R] looking for a plot function

[bogdan romocea]

Dear useRs,

I have a data frame and I want to plot all rows. Each row is
represented as a line that links the values in each column. The plot
looks like this:

dfr <- data.frame(A=sample(1:50,10),B=sample(1:50,10),
	C=sample(1:50,10),D=sample(1:50,10))
xa <- 10*1:4
plot(c(10,40),c(0,50))
for (i in 1:nrow(dfr)) {
	lines(xa,dfr[i,],pch=20,type="o")
	}

Things get more complicated because I want the columns to be rescaled
so as to fit nicely on a graph (for example if A has values between 0
and 100 but B has values between 100 and 1000, then rescale A or B),
labels etc. Is there a function that can do plots like this? 

Thank you,
b.