How to sync all my Facebook contacts to my iPhone?

Okay so I've had my Facebook all synced to my phone before but now when I go to my contact list, I only have about 15 of the 400 Facebook contacts there. I retried syncing the phone but still only 15 of my 400 Facebook contacts how up in my iPhone contact list. Does anyone know of this problem? What should I do to get All of my Facebook contacts back on my iPhone?

When you login in your account through your cellphone a page appears asking you that sync contacts or don't sync there you have to click on sync contacts then your problem will be solved.