Reservation train tickets

Hi,
Can you please reserve tickets from Beijing to Harbin on 15.02.17 Luxury Soft Sleeper departure 21:21 h arrival 16.02.17 07:26 h
for 1 adult Mariann Sandvik, 1 child Karl Abel Sandvik Karlsen and 1 child Noah Sandvik Karlsen?
To book on Web page I need passport number. My childrens passports are soon expiring, and I need to organize new ones for them. And I am afraid the tickets will be sold out while I am waiting for the new passports.
Please let me know as soon as possible. Thank you in advance.
Friendly regards Mariann from Norway.