public static function GetBestRankingOfTheMonth()
 {
     $month = date('m') * 1;
     $year = date('Y');
     if ($month == 1) {
         $month = 12;
         $year--;
     } else {
         $month--;
     }
     $month = $month * 1;
     if ($month < 10) {
         $month = "0{$month}";
     }
     $year_month = "{$year}{$month}";
     $ShortMonth = date('M', strtotime($year_month . '01'));
     $criteria = new CDbCriteria();
     $criteria->compare('month(t.received_on)', $month);
     $criteria->compare('year(t.received_on)', $year);
     $criteria->compare('t.status', STATUS_GEN_RECEIPT);
     $criteria->select = "t.user_id, SUM(t.received_commission) as received_commission";
     $criteria->group = "t.user_id";
     $criteria->order = "SUM(t.received_commission) DESC";
     $criteria->limit = 100;
     $models = self::model()->findAll($criteria);
     $uid = Yii::app()->user->id;
     foreach ($models as $key => $item) {
         if ($item->user_id == $uid) {
             $top = MyFormat::addOrdinalNumberSuffix($key + 1);
             return "You are top {$top} achiever for {$ShortMonth} {$year}";
         }
     }
     return '';
 }