start up problem

I have a macbook and having some problems on start up. I had my computer turned on (and sleeping) when i went to wake it up it was completley frozen, so i just powered it off. When I turned it back on i would get the folder w/ flashing question mark. I went to the apple sight and they said to use the disk utility off of the installation disk. When i try to use this for some reason it can't see my hard drive...

I've tried to get to the startup manager (by holding the option key) but I can't get that screen to pop up... it just goes grey, then eventually starts w/ the install disk. I've tried to do all the things on the startup but can't get them to work, not sure if i'm holding down the keys to late/early...

any tips would be appreciated! I am starting to think it might be the hard drive has crashed..

thanks for the link... as far as restart the PRAM by holding the 4 buttons. do push them imediately after you hit the power button, because its hard to time it before the grey screen comes up... doesn't seem to want to work for me.