protected function validate_doesnt_contain_list($field, $input, $param = null)
{
$param = trim(strtolower($param));
$value = trim(strtolower($input[$field]));
$param = explode(';', $param);
if (!in_array($value, $param)) {
// valid, return nothing
return;
} else {
return array('field' => $field, 'value' => $value, 'rule' => __FUNCTION__, 'param' => $param);
}
}