How to add terms and condition checkbox in Yii user module?

I am new in implementing Yii user module.I want to add a checkbox for terms and conditions on registration page and I dont know how I can add it.

Could any one help me to add terms and conditions checkbox.I find a rule from Yii forum:

array('agree', 'required', 'requiredValue' => 1, 'message' => 'Please   accept Terms and Conditons.'),

But I dont know where this rule will be define means in which models or controller.

Please Help me.