Upload image not working

Just i am start to learn yii. When i try to upload a image, i am getting empty value on submit.

This is my controller file code

public function actionCreate()


        $model=new Upload;



	  print_r($_POST['Upload']);    // it return file value is empty   


        $this->render('create', array('model'=>$model));


This is my model file code.

public function rules()


        return array(

             array('file', 'file','types'=>'jpg, gif, png'),




This is my view file code.

<div class="form">

<?php $form = $this->beginWidget(



        'id' => 'upload-form',

        'enableAjaxValidation' => false,

        'htmlOptions' => array('enctype' => 'multipart/form-data'),


); ?>

	<p class="note">Fields with <span class="required">*</span> are required.</p>

	<?php echo $form->errorSummary($model); ?>

	<div class="row">

		<?php echo $form->labelEx($model, 'file'); ?>

		<?php echo $form->fileField($model, 'file'); ?>

		<?php echo $form->error($model, 'file'); ?>


	<div class="row buttons">

		<?php echo CHtml::submitButton($model->isNewRecord ? 'Create' : 'Save'); ?>


<?php $this->endWidget(); ?>

My getting result is

Array ( [file] => ) 

Plse resolve my issue. Thanks in advance

Uploaded files are in $_FILES array, not in $_POST array.