About multilanguage!

I will develop a Gernman setup package,
i want to modify the default wording on dialog, and i want to change it in GUIinit function,
but i don't know how to declare and define the GUI function ?
can someone help me?
3ks!

zhe wei su zhou de peng you,xian zai dang di shi jian cai 7:30,mei you ren a.

hehe,
Thanks a lot for your reminder!
can you give me the e-mail for keeping correspondence?

wo xiang wo you hen duo yao xiang ni qing jiao de.