public function getGradeLevelName($id)
 {
     $level = GradeLevel::findOne($id);
     return $level['name'];
 }
use yii\bootstrap\Dropdown;
use app\models\Tuition;
use app\models\GradeLevel;
use app\models\SiblingDiscount;
$sbm = new SiblingDiscount();
$sbd = SiblingDiscount::find()->all();
if (!empty($array)) {
    $enrollment_float = $array[0]['enrollment'];
    $admission_float = $array[0]['admission'];
    $tuition_fee_float = $array[0]['tuition_fee'];
    $misc_fee_float = $array[0]['misc_fee'];
    $ancillary_float = $array[0]['ancillary'];
    $monthly_float = $array[0]['monthly'];
    $yearly_float = $array[0]['yearly'];
    $books_float = $array[0]['books'];
    $grade_level = GradeLevel::findOne($array[0]['grade_level_id'])['name'];
    $enrollment = number_format($array[0]['enrollment'], 2);
    $admission = number_format($array[0]['admission'], 2);
    $tuition_fee = number_format($array[0]['tuition_fee'], 2);
    $misc_fee = number_format($array[0]['misc_fee'], 2);
    $ancillary = number_format($array[0]['ancillary'], 2);
    $monthly = number_format($array[0]['monthly'], 2);
    $yearly = number_format($array[0]['yearly'], 2);
    $books = number_format($array[0]['books'], 2);
} else {
    $grade_level = 0;
    $enrollment = 0;
    $admission = 0;
    $tuition_fee = 0;
    $misc_fee = 0;
    $ancillary = 0;
 /**
  * Finds the GradeLevel model based on its primary key value.
  * If the model is not found, a 404 HTTP exception will be thrown.
  * @param integer $id
  * @return GradeLevel the loaded model
  * @throws NotFoundHttpException if the model cannot be found
  */
 protected function findModel($id)
 {
     if (($model = GradeLevel::findOne($id)) !== null) {
         return $model;
     } else {
         throw new NotFoundHttpException('The requested page does not exist.');
     }
 }