function cn_midstr($str,$start,$len){
	if($GLOBALS['cfg_ver_lang']=='utf-8'){
	  $str =  utf82gb($str);
    return gb2utf8(cn_substrGb($str,$slen,$startdd));
  }else{
  	return cn_substrGb($str,$slen,$startdd);
  }
}
function cn_substr($str, $slen, $startdd = 0)
{
    if ($charset == 'utf-8') {
        $str = utf82gb($str);
        return gb2utf8(cn_substrGb($str, $slen, $startdd));
    } else {
        return cn_substrGb($str, $slen, $startdd);
    }
}