Difference between #3 and #4 of An Easy Solution for Dependent dropDownList Using AJAX

Sometimes new Yii guys face problem to manage dependent dropDownList using AJAX.
I am going to discuss about an easy solution about this issue.

Example code:

Code in View-


~~~
[php]
<?php									
  echo CHtml::dropDownList('region_id','', 
  array(2=>'New England',1=>'Middle Atlantic',3=>'East North Central'),

  array(
    'prompt'=>'Select Region',
    'ajax' => array(
    'type'=>'POST', 
    'url'=>CController::createUrl('loadcities'),
    'update'=>'#city_name', 
  'data'=>array('region_id'=>'js:this.value'),
  ))); 
									 
								
 
echo CHtml::dropDownList('city_name','', array(), array('prompt'=>'Select
City'));
?>
~~~

Code in Controller-



~~~
[php]
public function actionLoadcities()
{
   $data=RegionCity::model()->findAll('region_id=:region_id', 
   array(':region_id'=>(int) $_POST['region_id']));
	 
   $data=CHtml::listData($data,'id','city_name');
		
   echo "<option value=''>Select City</option>";
   foreach($data as $value=>$city_name)
   echo CHtml::tag('option',
array('value'=>$value),CHtml::encode($city_name),true);
}
~~~

I think this will help to understand actually how AJAX works in Yii for
dependent dropDownList also AJAX working behavior in Yii framework.

--Enjoy, Explore... Yii