401K What should I do...?

Well, Im sure allot of people who have 401k's have been asking the same things over and over....Anyway....I HAD 15,000.00 in my 401K fund from work...July the roller coster hit bottom and I had lost over 12,000.00. To date I only have 650.00 in there....Yes WOW glad somebody is making money off this....I've talked to the advisors and they just say stay in and it will get better....Hmmmm I see that 4th quater returns are terrible and I'am already hearing about 1st quarter being the worst.....Since I have basically lost what I've worked so hard for....should I just pull out????