How can you change the locale of an application via a button on a web page. I am using struts and don't want the user to have to change their language from the browser (e.g. Tools-Internet Options-Languages in IE).

I want the user to be able to toggle languages from a button! This toggling only needs to be held throughout the lifecycle of the user's session. When the session ends the application will automatically use the browsers default language when a page is requested.