Ajax in checkBoxList don't check item after clicked

In my Yii project, I’m trying to use a checkBoxList to update another field in a form. But I’m having some issues if I add Ajax to update the other field.

Without Ajax, I can check and uncheck the items normally. With Ajax, the site sends the request, but the checkbox remains unchecked.

Example:




$selected = array(

    'item1_1',

    'item1_2',

);


$data = array(

    'item1'=>'test item 1',

        'item1_1'=>'test item 1.1',

        'item1_2'=>'test item 1.2',

        'item1_3'=>'test item 1.3',

    'item2'=>'test 2',

        'item2_1'=>'test item 2.1',

        'item2_2'=>'test item 2.2',

    'item3'=>'test item 3'

);


echo CHtml::checkBoxList('checklistbox_test',

    $selected,

    $data, 

    array(

        'class'=>'checklistbox_test_item',

        'ajax'=> array(

            'type'=>'POST',

            'url'=>Yii::app()->createUrl('site/contact'),

            'update'=>'#update_other_field',

            'data'=>array('filter_selected' => 'js:$(this).val()'),

        ),

    )

);



Maybe I would have to return that the item can be checked? But how?

Someone knows why this happens?