Phone Number Validation

$phone = new Text("phone" , array("class" => "form-control"));
$phone->setLabel("Phone Number");
$phone->addValidators(array(
    new PresenceOf(array(
        "message" => "Please fill in this number",
    )),
    new ExclusionIn(array(
        'message' => 'Number already registered',
        "domain" => $phone_list,
    )),
));