PHP function to clean html generated by word

<?php
/**
* 清理word产生的html
* by bbs.it-home.org
*/
function strip_word_html($text, $allowed_tags = '<b><i><sup><sub><em><strong><u><br>')
{
mb_regex_encoding('UTF-8');
$search = array('/&lsquo;/u', '/&rsquo;/u', '/&ldquo;/u', '/&rdquo;/u', '/&mdash;/u');
$replace = array('\'', '\'', '"', '"', '-');
$text = preg_replace($search, $replace, $text);
$text = html_entity_decode($text, ENT_QUOTES, 'UTF-8');
if(mb_stripos($text, '/*') !== FALSE){
$text = mb_eregi_replace('#/\*.*?\*/#s', '', $text, 'm');
}
$text = preg_replace(array('/<([0-9]+)/'), array('< $1'), $text);
$text = strip_tags($text, $allowed_tags);
$text = preg_replace(array('/^\s\s+/', '/\s\s+$/', '/\s\s+/u'), array('', '', ' '), $text);
$search = array('#<(strong|b)[^>]*>(.*?)</(strong|b)>#isu', '#<(em|i)[^>]*>(.*?)</(em|i)>#isu', '#<u[^>]*>(.*?)</u>#isu');
$replace = array('<b>$2</b>', '<i>$2</i>', '<u>$1</u>');
$text = preg_replace($search, $replace, $text);
$num_matches = preg_match_all("/\<!--/u", $text, $matches);
if($num_matches){
$text = preg_replace('/\<!--(.)*--\>/isu', '', $text);
}
return $text;
}