My son from India who is currently in Shanghai wants to marry chinese girl friend.Please advise

My son Amit from India is currently in Shanghai and is living there with her chinese girfriend, His travel visa is to expire on 16/06/2012 after getting it extended two times everytime for a month period. Now,both of them have decided to marry. Kindly advise suitably and urgently so that they can marry with eachother within ten days of period. He is single. He is worried now as he is nonworking there and timeleft for him is very less to stay in shanghai as his visa is expiring on 16th June 2012. Kindly asdvise where he should approach and how this marriage can be materialised within this period of ten days. regards GS Mahajan