[web] BBCode in PHP

//bbcode and smiliesfunction bbcode ($str) {    $str = htmlentities($str);    $token = array(                "'\[b\](.*?)\[/b\]'is",                                                  '/\[i\](.*?)\[\/i\]/is',                                                '/\[u\](.*?)\[\/u\]/is',       				'/\[url\=http:\/\/(.*?)](.*?)\[\/url\]/is',                                         '/\[url\=(.*?)\](.*?)\[\/url\]/is',                                         '/\[url\](.*?)\[\/url\]/is',                                             '/\[align\=(left|center|right)\](.*?)\[\/align\]/is',                    '/\[img\](.*?)\[\/img\]/is',                                            '/\[mail\=(.*?)\](.*?)\[\/mail\]/is',                                    '/\[mail\](.*?)\[\/mail\]/is',                                            '/\[font\=(.*?)\](.*?)\[\/font\]/is',                                    '/\[size\=(.*?)\](.*?)\[\/size\]/is',                                    '/\[color\=(.*?)\](.*?)\[\/color\]/is',                        );    $tokenized = array(                '$1',                '$1',                '$1',				'$2',                '$2',                '$1',                '
$2
',                '<img src="$1" />',                '$2',                '$1',                '$2',                '$2',                '$2',                );    // Do simple BBCode's    $str = preg_replace ($token, $tokenized, $str);    // Do <blockquote> BBCode    $str = embedded ($str);    return $str;}function embedded ($str) {    $open = '<blockquote>';    $close = '</blockquote>';    // How often is the open tag?    preg_match_all ('/\[quote\]/i', $str, $matches);    $opentags = count($matches['0']);    // How often is the close tag?    preg_match_all ('/\[\/quote\]/i', $str, $matches);    $closetags = count($matches['0']);    // Check how many tags have been unclosed    // And add the unclosing tag at the end of the message    $unclosed = $opentags - $closetags;    for ($i = 0; $i < $unclosed; $i++) {        $str .= '</blockquote>';    }    // Do replacement    $str = str_replace ('[' . 'quote]', $open, $str);    $str = str_replace ('[/' . 'quote]', $close, $str);    return $str;}