my cd/dvd drive no longer works....is it toast?

What version of Mac OS X are you running on the Macbook?

Go to Apple Menu / About This Mac / More Info.

In the new window, in the left column, under hardware, select Disk Burning. Does the optical drive appear on the right?

If it does not, the burner is indeed dead. But - a big but, even if the drive is listed, it is not necessarily working.

Have you run the Apple Hardware Test?