// controller
// calls library function
$about->contactDetails($this->getRequest()->getPost())

// library
// calls private function fo the form
public function contactDetails()
{
...
$this->_getContactForm($mobile, $email);
...

// library
// function that calls the form
protected function _getContactForm($mobile = false, $email = false)
{
    require_once APPLICATION_PATH . '/forms/Contact.php';
    $form = new Form_Contact();
    $form->setAction('/about/contact');
    $form->contactDetails($mobile, $email);

return $form;
}

// the form
class Form_Contact extends Zend_Form
{
	/*
	* display values for changing current vault password
	*/
    public function contactDetails($msisdn = false, $email = false)
    {
        // set the method for the display form to POST
        $this->setMethod('post');

		$this->addElement('text', 'mobile', array(
			'label'      => 'Mobile Number:',
			'required'   => false,
			'validators' => array(
				array('validator' => 'Digits'),
				array('stringLength', false, array(10, 20))
				)
		));

        $this->addElement('text', 'email', array(
            'label'      => 'Email Address:',
            'required'   => false,
            'validators' => array(
                array('validator' => 'EmailAddress')
                )
        ));

        // add the submit button
        $this->addElement('submit', 'submit', array(
            'label'    => 'Update',
        ));
    }


}