About the char16 and char(16);

hi,
Can somebody tell me the difference in char16, char(16)?
I found a .c program in the package of the v6.3 of postgres that can
concat two char16 strings to one, is there any method that can easily
concat two char(80) or char(30) to a string?

--
Regards, Christopher Luk
   System Analyst - The Hong Kong Council of the Church of Christ in
China
              Phone : (852) 2397-1022 Fax : (852) 2397-7405
     mailto:wluk@hkcccc.org URL : http://www.hkcccc.org (Chinese based)