api/manage/sku.php

<?php
return array
(
    'update' => array
    (
        'field'    => array
        (
            'key' => array
            (
                'type' => 'hidden',
                'remote' => 'api/manage.keyToField',
            ),
            'price' => array
            (
                'type' => 'text',
                'rules' => true,
            ),
            'num' => array
            (
                'type' => 'text',
                'rules' => true,
            ),
            'day_num' => array
            (
                'type' => 'text',
                'rules' => true,
            ),
        ),
    ),
);