[R] How to install older version of R?

[Pan, Jia-chiun/潘家群]

Dear list

	This is much like a linux problem, but I can't find any reference for
it. My OS is ubuntu 9.04 and a version of 2.9.2 of R has been already
installed in. Now, I need to install the version of 2.7.1. I google a
lot of websites and it seems like without a painless way provided me to
do it.
	If any one offer me some suggestions/reference, I will appreciate.

								Jia-Chiun Pan