$form = new Varien_Data_Form(); $form->setId('my-form');
class My_Form extends Varien_Data_Form { public function __construct() { parent::__construct(); $this->setId('my-form'); } }In this example, a custom form class called My_Form is created that extends Varien_Data_Form. Its constructor calls the parent constructor and sets the form's ID to "my-form". This method is part of the Varien package library in the Magento PHP framework. The Varien package library is a collection of classes and methods that provide common functionality for Magento developers.