class Application_Form_ContactForm extends Zend_Form
{
        public function __construct($options = null)
        {
                parent::__construct($options);
                $this->setName('envia_sms')
            ->setMethod('get');

                $username = new Zend_Form_Element_Hidden("username");
                $username->setValue("blah");

                $password = new Zend_Form_Element_Hidden('password');
                $password->setValue('bleh');

                $number = new Zend_Form_Element_Text('to');
                $number->setLabel('Numero')
                        ->setRequired(true)
                        ->addValidator('NotEmpty')
                        ->addValidator('Digits');

                $message = new Zend_Form_Element_Textarea('text');
                $message->setLabel('Mensagem')
                        ->setRequired(true)
                        ->addValidator('NotEmpty')
                        ->addValidator('StringLength', false, array(0,160));

                $submit = new Zend_Form_Element_Submit('submit');
                $submit->setLabel('Enviar SMS');

                $this->addElements(array($username, $password, $number, $message, $submit));

        }
}


------ Controller ------


class IndexController extends Zend_Controller_Action
{

        public function init()
        {
                /* Initialize action controller here */
        }

        public function indexAction()
        {
                $this->view->pageTitle = "Zend_Form Example";
                $this->view->bodyCopy = "<p >Please fill out this form.</p>";

                $form = new Application_Form_ContactForm();
                $data = array( 'username'=> 'bleh' );
                $form->populate( $data );

                if ($this->_request->isGet()) {
                        $formData = $this->_request->getQuery();
                        if ($form->isValid($formData)) {
                                echo 'success';
                                exit;
                        } else {
                                $form->populate($formData);
                        }
                }

                $this->view->form = $form;
        }


}

----------------------- OUTPUT ------------------------


Zend_Form Example<p >Please fill out this form.</p>
<form id="envia_sms" enctype="application/x-www-form-urlencoded" action="" method="post"><dl class="zend_form">
<dt id="username-label">&#160;</dt>
<dd id="username-element">
<input type="hidden" name="username" value="" id="username"></dd>
<dt id="password-label">&#160;</dt>
<dd id="password-element">
<input type="hidden" name="password" value="" id="password"></dd>
<dt id="to-label"><label for="to" class="required">Numero</label></dt>
<dd id="to-element">
<input type="text" name="to" id="to" value="">
<ul class="errors"><li>Value is required and can't be empty</li><li>Invalid type given, value should be string, integer or float</li></ul></dd>

<dt id="text-label"><label for="text" class="required">Mensagem</label></dt>
<dd id="text-element">
<textarea name="text" id="text" rows="24" cols="80"></textarea>
<ul class="errors"><li>Value is required and can't be empty</li><li>Invalid type given, value should be a string</li></ul></dd>
<dt id="submit-label">&#160;</dt><dd id="submit-element">
<input type="submit" name="submit" id="submit" value="Enviar SMS"></dd></dl></form>