Lenny. Locales and Interface Language

[Mark Goldshtein <mark.goldshtein@gmail.com>]

Hello, list!

Would you, please, help me to explain how locales work in Lenny? I
have checked docs but something remains unclear. If you have time,
please, answer a few questions below:

1. Is a default system locale independent from an interface language?
I mean, is it possible to change a default system locale to whatever I
like and there will be no harm to English interface I have?

2. Is it will be enough to switch a default system locale via #
dpkg-reconfigure locales
?
In this case, locales I have chosen before, will be regenerated and
there will be no harm to current set of locales and I will have a
chance to change default system locale, right?

3. Is that correct method to change default system locale or I should
use another one, like to edit some configuration files manually?

4. Do I need to reboot the system after that 'dpkg-reconfigure locales'?

Thanks for your time and effort!

-- 

Sincerely Yours'
Mark Goldshtein