Hard drive wont mount

Ok Im not techie, but before I pitch this thing I would like to see if there is a fix that won't cost me an arm and a leg.

My laptop wont start up. It has (had?) 10.5.8 on it I don't have the disk for that but I do have a disc for 10.5.6

If I start up I get the happy face/question mark icon....wont go further. If I insert the 10.5.6 disc, it goes to the screen to select drive to install on, the box is blank. No drive to pick from.

If I go to the top and select disk utility, the only disk to choose is the dvd.

Is my laptop toast? I know it is old, but I cannot afford another and this was working awesome til it blew its cork.

Thanks ever so much for any help you can give me.