[R] cumulative distribution functions

[Monica Palaseanu-Lovejoy]

hi y'all,

I am wondering if there is any special command, function, 
package, etc to help me doing a cumulative distribution function, 
with y-scale - probability scale.

I tried the help in R and i got the following answers:
cumsum(base)            Cumulative Sums, Products, and Extremes
ecdf(stepfun)           Empirical Cumulative Distribution Function
cpgram(ts)              Plot Cumulative Periodogram

But i could not find either (stepfun) nor (ts) packages to read the 
specific help. Are they discarded? The "cumsum" seems not to do 
what i really was after.

Any help as usual very much appreciated ;-)

Monica