function validate ($data, $check_required=True, $use_default=True) {
        $default = array(
            'code' => array(
                'required' => True,
                'validate' => is_string
            ),
            'name' => array(
                'required' => True,
                'validate' => is_string
            ),
            'active' => array(
                'required' => False,
                'validate' => is_bool,
                'default' => False
            ),
            'from' => array(
                'required' => False,
                'validate' => is_string,
                'default' => ''
            ),
            'to' => array(
                'required' => True,
                'validate' => is_string
            ),
            'subject' => array(
                'required' => False,
                'validate' => is_string,
                'default' => ''
            ),
            'body' => array(
                'required' => False,
                'validate' => is_string,
                'default' => ''
            )
        );
        $errors = array();
        $fields = array();
        foreach ($default as $key => $rules) {
            if (empty($data[$key])) {
                if ($rules['required']) {
                    if ($check_required) {
                        $errors[] = "Field $key is required";
                    }

                    continue;
                }
                if ($use_default) {
                    $fileds[$key] = $rules['default'];
                }

                continue;
            }

            if (!$rules['validate']($data[$key])) {

                $errors[] = "Validation failed on $key = $data[$key]";
            }

            $fields[$key] = $data[$key];
        }

        print_r($fields);
        return array($errors, $fields);
    }