By the way. When I change the duku.php from ASCII to UTF-8 code. The error message will only like this:
Warning: Cannot modify header information - headers already sent by (output started at D:\freehost\howiehu2006\web\dokuwiki\inc\init.php:102) in D:\freehost\howiehu2006\web\dokuwiki\inc\auth.php on line 244
Warning: Cannot modify header information - headers already sent by (output started at D:\freehost\howiehu2006\web\dokuwiki\inc\init.php:102) in D:\freehost\howiehu2006\web\dokuwiki\inc\actions.php on line 131