关于夜火车求助！！

我搜了前人的贴子，知道可以从http://www.thetrainline.com/上查火车票，我想查伦敦到爱丁堡的夜火车

但是当我选了一个大人一个孩子的时候，点击查询结果显示了下面的内容

“However, there are children in your Booking request. If you wish to book children

on the Sleeper service, please call 08704 111 111 where a member of thetrainline staff

will be pleased to assist you.Alternatively, if you wish to travel by any other service,

please continue.”

这是咋回事呀