mac won't start up

Hi

I have searched for an answer and can't find one, I have a macbook pro, It won't start up, I can access mac OS x utlities, I went to reinstail mac snow leapard but have no file to instail it to.

In Disk utility t don't see the hard drive. I have a current back up, however I have no where to back it up to.

What am I missing.... My Hard Drive?

Thanks in advance

Gary