Johnson,
If you look here:
http://api.cakephp.org/1.2/l10n_8php-source.html#l00180
You'll find that the code you are trying to use is set with "-"
instead of "_".
I think the codes must be used as defined in this array.
Here you have some additional info:
http://bakery.cakephp.org/articles/view/
i want to support eng and zh_tw in my website.the locale's directories
are
app\locale\eng\LC_MESSAGES\default.po
app\locale\zh_tw\LC_MESSAGES\default.po
then, i use $this->Session->write('Config.language', $language); to
control current language.
if i want to display english , i set $language='