You can set the Default Language for your server which is used for all the end user error messages using the Magnus Editor from the server preferences. The localized version of Sun Java System Web Server 6.1 supports seven languages:
zh (Simplified Chinese)
zh_TW (Traditional Chinese)
The end-user search interface in a localized version of the Sun Java System Web Server 6.1 is completely localized.
This setting has no effect on a non-localized version of the web server.