[Wiki] How to show a Captcha in CForm?

class MyCaptcha extends CCaptcha
{
   public $model;
   public $attribute;
 
   public function run(){
 
       parent::run();
       echo CHtml::activeTextField($this->model, $this->attribute);
    }
}

public function actions()
 {
   return array(
      'captcha'=>array(
      'class'=>'CCaptchaAction',
      'backColor'=>0xFFFFFF,
     ),
   );
}

return array(
    'title'=>'Please provide your login credential',
 
    'elements'=>array(
        'username'=>array(
            'type'=>'text',
            'maxlength'=>32,
        ),
        'password'=>array(
            'type'=>'password',
            'maxlength'=>32,
        ),
        'verifyCode'=>array(
              'type'=>'MyCaptcha',   //render the captcha image & text field.
              'showRefreshButton'=>false,
              'clickableImage'=>true,
     ),
    ),
 
    'buttons'=>array(
        'login'=>array(
            'type'=>'submit',
            'label'=>'Login',
        ),
    ),
);