hello,everyone:
when i try to install punbb 1.3 on my server, i receive the following error:
Fatal error: Call to undefined function utf8_decode() in /mnt/sda1/www/include/utf8/native/core.php on line 32
who can help me to fix it , thanks! 
my server environment:
lighttpd: 1.4.28
PHP: 5.3.6
SQLite 2.8.17