private function checkContactFields($contact)
{
// Check Contact information
$contact_types = array('owner_contact', 'admin_contact', 'tech_contact', 'billing_contact');
for ($contact_type = 0; $contact_type < count($contact_types); ++$contact_type) {
if (!isset($contact->{$contact_types[$contact_type]})) {
Exception::notDefined($contact_types[$contact_type]);
}
for ($i = 0; $i < count($this->contactRequiredFields); ++$i) {
if (!isset($contact->{$contact_types[$contact_type]}->{$this->contactRequiredFields[$i]}) || $contact->{$contact_types[$contact_type]}->{$this->contactRequiredFields[$i]} == '') {
Exception::notDefined("{$this->contactRequiredFields[$i]} in {$contact_types[$contact_type]} ");
}
}
}
}