Forum OpenACS Development: how can i change the default display character-set?

I am now using OpenACS 4.5, and trying to create new contents.
A default character set display problem is confusing me now. I build up my site, it's working now, but when I tried to access the site by browser, the default font character-set is iso-8859-1.
I wish the default font character-set could be Chinese-traditional(big5), is there any configuration I can do to make this happen?
I am not sure weather my expression is clear enough. If my question is not clear enough, please let me know, I'll try to make it clearer.
Which version of AOLserver are you using?  Not all versions support other character sets.  The OpenACS distribution at http://uptime.openacs.org/aolserver-openacs/ includes internationalization support and the recent AOLserver 4 betas should too.  (There are patches for a few other 3.x versions, but you would have to recompile AOLserver.) I believe the configuration might be a little different depending on which version you are using.