[R] about Cox-Box transformation

[Stefano Sofia]

Dear R-users,
I am using R version 1.8.0-1 under Suse 8.2. 
I need to use the boxcox command because I want to apply a Cox-Box
transformation to a vector of rainfall values. 
Within the libraries, the MASS library is present, but I don't know
whether this means that is automatically installed or not.
The command doesn't work. What do I have to do in order to make it
working? Is just a problem of installation or simply of recalling the
right command?

thank you for your help
Stefano