Contact form with Zend Framework

Contact.php

<?php

/* /library/Square/Form/Contact.php */

class Square_Form_Contact extends Zend_Form
{

    public function init()
    {

        $this->setAction('/contact')
                ->setMethod('post');

        $name = new Zend_Form_Element_Text('name');
        $name->setLabel('Name:')
                ->setOptions(array('size' => '35'))
                ->setRequired(true)
                ->addValidator('NotEmpty', true)
                ->addValidator('Alpha', true, array('allowWhiteSpace' => true))
                ->addFilter('HtmlEntities')
                ->addFilter('StringTrim');

        $email = new Zend_form_Element_Text('email');
        $email->setLabel('Email address:')
                ->setRequired(true)
                ->addValidator('NotEmpty', true)
                ->addValidator('EmailAddress', true)
                ->addFilter('HtmlEntities')
                ->addFilter('StringToLower')
                ->addFilter('StringTrim');

        $message = new Zend_Form_Element_Textarea('message');
        $message->setLabel('Message:')
                ->setOptions(array('rows' => '8', 'cols' => '40'))
                ->setRequired(true)
                ->addValidator('NotEmpty', true)
                ->addFilter('HtmlEntities')
                ->addFilter('StringTrim');

        $captcha = new Zend_Form_Element_Captcha('captcha', array(
            'captcha' => array(
                'captcha' => 'Image',
                'wordLen' => 6,
                'timeout' => 300,
                'width'   => 300,
                'height'  => 100,
                'imgUrl'  => '/assets/captcha',
                'imgDir'  => APPLICATION_PATH . '/../public/assets/captcha',
                'font'    => APPLICATION_PATH . '/../public/assets/fonts/LiberationSansRegular.ttf'
            ))
        );
        $captcha->setLabel('Verification code:');

        $submit = new Zend_Form_Element_Submit('submit');
        $submit->setLabel('Send Message')
                ->setOptions(array('class' => 'submit'));

        $this->addElement($name)
                ->addElement($email)
                ->addElement($message)
                ->addElement($captcha)
                ->addElement($submit);

    }   

}