Currently Being ModeratedNov 29, 2012 11:19 AM (in response to Pamela Jeanne)
Your options are to use a stonger disk repair utility like DiskWarrior, or reformat the hard drive and reinstall from your backup or bring it to an Apple store in case the drive is toast. You are under warranty.
Currently Being ModeratedNov 29, 2012 11:20 AM (in response to Pamela Jeanne)
Welcome to the Apple Support Communities
If you have a backup, erase the drive and reinstall OS X. To do this, press Command and R keys while your computer is starting. If it doesn't solve this issue, the hard drive is damaged and you have to take the Mac to an Apple Store. The repair will be free of charge
Currently Being ModeratedNov 29, 2012 11:24 AM (in response to mende1)
I'm just reporting what others have reported here but if you take it to a store make sure it is backed up first. They sometimes do not consider saving your files first as part of the service in, say, installing a new hard drive, especially if it requires doing extra steps in file recovery.