Parameter Pass As Post Use Link

How to multiple parameter pass as post by using CHtml::link and get parameter value from controller action ?

Like as

$url = array('Exams/displaySubject');
echo CHtml::link(
$val['exam_groups_name'], $url, array(
'submit' => $url,
'params' => array('exam_groups_id' => $val['exam_groups_id'], 'batch_id' => $val['batch_id']),
)
);

But i can't understand is it working ? Because I can not get parameter value in controller action. if it is right code then how to get parameter value from controller action ? So help any one plz. solve the problem ?