I got my new MGMAT SC 2007 book a couple of minutes ago. I have a code on the back page of the book. But I couldn't enter STUDENT CENTER and i couldn't access to online 6 tests. The following message popped up:

[b] "Thank you for visiting Manhattan GMAT.Online practice problems and exams are accessible only to current Manhattan GMAT students.
Access can also be purchased separately by visiting our online store.If you were a Manhattan GMAT student or already purchased
access separately and are still seeing this message, your access has expired."[/b]

Could anyone here help me overcome this difficulty.
I highly appreciate ur help. Thank you.