[fw-mvc] Zend Dojo Form Doesn't Display Validation Errors

The form displays, but nothing happens when the form is blank and you
click on the submit button. Any idea why it's not being sent back to
the controller for validation?

-Ed

class Test2Form extends Zend_Dojo_Form {

public $drivers = array("-- Select --", "Rob Allen", "Charlie Brown",
"Lucy van Pelt");

public function __construct($options = null) {
parent::__construct($options);
$this->setName('mileagelog');

$user_id = new Zend_Form_Element_Select('user_id');
$user_id
->setLabel('Driver:')
->setMultiOptions($this->drivers)
->setRequired(true)
->addErrorMessage("Please choose a driver.")
->addValidator(new Zend_Validate_GreaterThan(0));
$this->addElement($user_id);

$logDate = new Zend_Dojo_Form_Element_DateTextBox('logDate');
$logDate
->setLabel('Log Date')
->setRequired(true)
->addValidator('NotEmpty')
->addErrorMessage("Please provide a date.");
$this->addElement($logDate);

$submit = new Zend_Form_Element_Submit('submit');
$this->addElement($submit);

}
}