how to change mysql default character set?

[xdiy]

my os is freebsd 6.1,ande with the default character latin1 of mysql 4.1

I need to

character set client (Global value) ---latin1
character set connection (Global value) -----latin1
character set database ------------latin1
character set results (Global value) -----latin1
character set server ---latin1

all this change to gbk

collation connection (Global value) ---latin1_swedish_ci
collation database--- latin1_swedish_ci
collation server--- latin1_swedish_ci

all this change to gbk_chinese_ci


who can tell me,how to change charset to my define option?

help me!!!!!~~~~
thanks a lot!!