how to update rails 2 to rails 3

Hi,

I m new to rails. I have funny things when trying to change version of
rails.
I have installed ruby 1.6.5.1 and ruby 1.9.3. I installed RVM and
everything correctly.

When i change ruby version with rvm use 1.9.3 it succesfully change
ruby, when type
ruby -v it shows 1.9.3 .

But then I try to install rails 3 with rvm gem install rails, it shows
rails 3.2.6 is sucesfully installed but when I type rails -v it shows
2.8.6 again.

When i type gem rails list it shows that 2.8.6 and 3.2.6 are installed,
but how can I make terminal
shows 3.2.6 when I run rails -v command?

Also how can I use jruby 1.6.5.1 as ruby 1.9?
And how to create sucesfully new project specifzing version for example>

rails _3.2.6_ new test

When I try it shows me errors.

Thanks in advance

But then I try to install rails 3 with rvm gem install rails, it shows
rails 3.2.6 is sucesfully installed but when I type rails -v it shows
2.8.6 again.

When i type gem rails list it shows that 2.8.6 and 3.2.6 are installed,
but how can I make terminal shows 3.2.6 when I run rails -v command?

If you're using rvm, you should create separate gemsets for Rails 2 and 3.
(And "2.8.6" isn't a version of Rails I've ever encountered...)

Also how can I use jruby 1.6.5.1 as ruby 1.9?

jruby --1.9 # see also: jruby --help

And how to create sucesfully new project specifzing version for example>

rails _3.2.6_ new test

When I try it shows me errors.

What errors, exactly?

Thanks for replies. When I try to run rails new app it shows me

Cant find gem rails with executable rails.

I also tried rails _3.2.6_ --version it shows me the same error.
It seems like rails not installed but I runned gem install rails

When I type gem list rails it shows me

rails (3.2.6)

I use mac.

What can be a problem?

Could you please post the content of your path and also where gems are installed? Perhaps you could try bundle exec rails new etc

This is solved thanks to my college.

Thanks you all on answers.

Can you please tell us the solution?

RVM was installed with sudo by my administrator and then it was problem
because ordinary user
doesnt have permision to pull gems. So chief of administrators
reinstalled RVM and everything works fine.

Thanks for answers