MacBook don't boot after disk repair from recovery

Hi,

a few hour ago for a very little problem with finder (view previous discussion) and just for a curiosity i've checked my disk with disk utility and i've found some errors on the main disk. When repair is finished i see a message that say that is necessary to boot in recovery mode for completely repair my disk.

I booted from usb installation of mountain lion and select disk utility, check disk, start to repair it and at the end i see a message that say the disk can't be repaired and is important to make a backup of content, initialize it and reinstall OS on it but when i restart my mac, this will not boot anytime. I see an horizontal progress bar (moooore slow) and after complete the progress bar i see the circle spinner turning but don't start (also after 30min).

What can i try for solve this problem???