How to set Locale dynamically

[thenakedsingularity]

Still a newbie to SpringMVC, so please be patient.

I want to do the following:

Support both english and spanish in my webapp. User can change the
language per session by clicking on some radio button on a config page.
Field lable is the only thing needs the multilingual support for this app.

What Spring components do I need to accomplish this?

I have not seen any books or resources that explain this issue in detail.

Thanks for your help.

[thenakedsingularity]

I don't want to maintain two sets of JSPs.