Thanks and few more questions

Thank all of you very much for your response. Could you please answer few more questions for us?
1)From other resources http://edu.sinohome.com/oversea/papers/1059.htm and http://www.chinapressusa.com/20040814/life/lifeedu/200408140158.htm, is it true that we should provide a 寄养儿童委托书 so he would be able to live in China after his travel permit in China is due? The permit is valid for only one year and it is very difficult for us to make the 寄养儿童委托书 right now.
2)If we don't give a 寄养儿童委托书, Will our child get trouble in living China and then leaving China in the future?
YOur advices and informaton would be highly appreciated!