I think shahhid ali means they have a serial for Logic 8.
Logically, this is all they can mean if you eliminate the possibilities.
shahhid ali, what OS are you running on your Macbook? If it is not Mavericks (10.9.x) then Logic 8 will work on your computer. The installer won't work but there are ways around that if you have your original discs.
If you are running Mavericks (10.9.x) then Logic 8 will not run on your Macbook so you'll either have to install an earlier OS (if it can take it) or buy Logic X from the app store for $199 or however much it is in your county's app store.
ps, Norm123, I have supplied feedback several times to Apple to say when an Apple Community Specialist replies to a post, the icon on the front page turns into an Apple logo and no one else can see if the issue is solved or on-going. It is very very annoying for those of us who have been here years trying to help people. Can you please pass this on to someone. It does not show community spirit.