LOL
he probably wanted to advertise you with his message
anyway, I hope none there will give their precious cd-key ! even to your best friend !
you really never know how stupid, they are sometimes and that's with that way that you find YOUR cd-key published Online !
Special message for that guy :
-Learn & Study: there's many manuals & helpful writings on the net, if you really want it, you'll find what you're searching for
AND ! of course if you use the game more than a few times go buy a second copy for your friend!