Hi. I recently bought new MacBook Air (the 2011 model). My friend brought it to me from the states, however im from Czech Republic. I would like to change the plug from the US power plug to czech one. I just got rid off the american plug, but surprisingly the cable had different colors inside than i am used to in czech cables.. I see white, black and green cable.. Im used to black one as the fuse (the cable with electricity) yellow with green stripe being a cable for ground and the blue one for negative. And im not sure which cable is which in the power chord from the macbook. Can you please tell me how this works in us. I had a macbook from US before, but the colors of cables were also different from these one. So please help. Thanks, Pavel.