public function donations()
 {
     if (!empty($_POST)) {
         $price1 = "100";
         $price2 = "200";
         $price3 = "400";
         $err = array(0, 0);
         if (isset($_POST['money'])) {
             $money = $_POST['money'];
         }
         if ($money == $price1 or $money == $price2 or $money == $price3) {
             $err[0] = 0;
         } else {
             $err[0] = 1;
         }
         if (isset($money)) {
             if ($err[0] != 0) {
                 return $err;
             } else {
                 $err[1] = 1;
                 Model_donations::counting();
                 return $err;
             }
         }
     }
 }