if (!$week || ($week == "")) {
     $lastday = date("t", mktime(0,0,0,$month,1,$year));
     $temp = (date("w",mktime(0,0,0,$month,$lastday,$year)) - $day_of_week) % 7;
} else {
     $temp = ($day_of_week - date("w",mktime(0,0,0,$month,1,$year))) % 7;
}