function js_unescape($str)    {        $ret = '';        $len = strlen($str);        for ($i = 0; $i < $len; $i++)        {            if ($str[$i] == '%' && $str[$i+1] == 'u')            {                $val = hexdec(substr($str, $i+2, 4));                if ($val < 0x7f) $ret .= chr($val);                else if($val < 0x800) $ret .= chr(0xc0|($val>>6)).chr(0x80|($val&0x3f));                else $ret .= chr(0xe0|($val>>12)).chr(0x80|(($val>>6)&0x3f)).chr(0x80|($val&0x3f));                $i += 5;            }            else if ($str[$i] == '%')            {                $ret .= urldecode(substr($str, $i, 3));                $i += 2;            }            else $ret .= $str[$i];        }        return $ret;    }