HELP! Whats wrong with my macbook?

ok, so i have NEVER had a problem with my charger, and then i left my charger at a friends and it got switched with his. i have been using it for about a month now, his seems a little more beat up and just now at work, i plugged my charger in to a power strip and continued surfing. all of a suddenly i hear a BUZZZ noise and i see a little smoke come from where my charger plugs into my computer!!! so i unplugged it real fast and it smelt like burning. WHAT DO I DO? DO YOU THINK MY COMPUTER IS MESSED UP? its running fine for now, do you think it is anable to charge now? WHAT DO I TELL MY FRIEND?