Issue with checkbox on zend framework 1

[manjava]

I have an issue with a checkbox: it does not update to the database.

$emailnotification = new Zend_Form_Element_Checkbox('emailnotification ', 'emailnotification', array(
    'checkedValue'  => 1,
    'uncheckedValue' => 0,
) );
$emailnotification->setLabel('emailnotification');
$emailnotification->setValue(1);
$this->addElement($emailnotification);

and on Controller I have action update the following code below for update:

if($this->_request->isPost())
{
    $formData = $this->getRequest()->getPost();
    if($form->isValid($formData))
    {
        $contact = new Admin_Model_DbTable_Contact();
        $data = array();
        $data['idContact']            = $idContact;
        $data['firstname']            = $form->getValue('firstname');
        $data['lastname']             = $form->getValue('lastname');
        $data['emailnotification']    = $form->getValue('emailnotification');
        if($contact->editContact($data))
        {
            echo json_encode(array(
                "response"   => true,
                "message"    => "Contact " . $data['firstname'] . " " . $data['lastname'] . "a été modifié"
            ));
            exit();
        } else {
            echo json_encode(array(
                "response"     => false,
                "errorMessage" => "Il y a eu une erreur dans l'edition de Contact."
            ) );
            exit();
        }
    }
}

function editcontact:

public function editContact(array $data) { if(!empty($data)) { if($this->update($data, array('idContact = ?' => $data['idContact'])) > 0 ) { return true; } return false; } return false; }

on .phtml

$('#editContact').submit(function(event)
{
    var formId = $(this).attr('id');
    // Stop full page load
    event.preventDefault();
 
    //Request
    var data = {
        // contact's properties 
        firstname               :       $("#firstname").val(),
        lastname                :       $("#lastname").val(),
        emailnotification       :       $("#emailnotification").val(),
        batnotification         :       $("#batnotification").val()
 
    };  
 
    // Send
    $.ajax({
        url: $('#'+formId).attr('action'),
        dataType: 'json',
        type: 'POST',
        data: data,
        success: function(data, textStatus, XMLHttpRequest)
        {                    
            if (data.response == true)
            {
                alert(data.message);
                //upContent('userManagement/index/','');
 
 
 
            }
            else
            { 
                alert(data.message);
            }

and not worked for me always message Undefined and not update the data base

Thanks in advance