[ESS] Problem with ? in R when using ECB

[Scionforbai]

What should I set to get the help messages (with ?command) in the
browser and not in another emacs frame?
I start R with M-x R, in the R process I set options(browser='path to
firefox'); then with help.start() i get the doc index in firefox, but
with any further help() or '?' in the R process I only get other emacs
buffer.
Sorry for the newbieness of the question ...