The ghost from the past is my MySQL database encoded in tis620. Worse, the table and the column itself is labelled as iso-8859-1. Of course, if the web page is to be "viewed" as tis620, all I must to is to simply use
SET NAMES tis620; SET CHARACTER SET tis620;
In my php code. However, this is not the case because the page itself is utf8.
What comes to help me is iconv. In short, this is what I did.