Agan semua minta bantuan Dependent dropdown ga bisa,
kalo yang prodi sudah, tapi matakuliah pada masing-masing prodinya ga bisa muncul salah dmn ya 
saya punya dua tabel
prodi
|idprodi|
|nama|
matakuliah
|idmatakuliah|
|nama|
|idprodi|
Controller
	public function actionMatkul()
{
    $data=Matakuliah::model()->findAll('idprodi=:idprodi', 
                  array(':idprodi'=>(int) $_POST['idmatakuliah']));
 
    $data=CHtml::listData($data,'idmatakuliah','nama');
    foreach($data as $value=>$name)
    {
        echo CHtml::tag('option',
                   array('value'=>$value),CHtml::encode($name),true);
    }
}
trs formnya
	<div class="row">
        <?php echo $form->labelEx($model,'id_prodi'); ?>
        <?php echo $form->dropDownList($model,'id_prodi',
                CHtml::listData(Prodi::model()->findAll(), "idprodi", "nama"),
                array(
                        'empty'=>'Pilih Prodi',
                        'ajax'=>array(
                                'type'=>'POST',
                                'url'=>CController::createUrl('Sap/Matkul'),
                                'update'=>'#'.CHtml::activeId($model, 'idmatakuliah')
                        ),
                )) ?>
        <?php echo $form->error($model,'id_prodi'); ?>
	</div>
	<div class="row">
        <?php echo $form->labelEx($model,'id_matakuliah'); ?>
        <?php echo $form->dropDownList($model,'id_matakuliah',
                array(), // initially empty
                array('empty'=>'Pilih Matakuliah')) ?>
        <?php echo $form->error($model,'id_matakuliah'); ?>
	</div>