source("http://bioconductor.org/biocLite.R")

major <- as.numeric(R.Version()$major)
minor <- as.numeric(R.Version()$minor)

if (major == 2 && (minor >= 12 && minor < 13)) {
  ##ok
} else {
  stop("You must be running R version 2.12") 
}

courseRepos <- "http://bioconductor.org/course-packages"
allRepos <- c(courseRepos, biocinstallRepos())