okay i'm selling my macbook air and i'm wanting to know if i could take it to the apple store and have them erase and reinstall leopard or snow leopard for me? i dont have the original disc that came with it so i don't know how to erase all my stuff off of it and i'm supposed to be meeting the guy tomorrow at noon to give it to him... but we're meeting at the apple store so if i took it in there could they just do it for me?