Newbish Function Problem

Ok, just for fun I am making a game that involves a function that makes a bottle randomly explode in all directions. The function is on the main frame of my game and is linked to several movie clips inside the bottle. When the conditions are right, the movie clips should call the function and then fly out in random directions. The problem is, when i put the code directly onto the movie clips it works fine, but when i attempt to use it as a function is makes the entire movie move in random directions instead of the glass shard. My only guess as to why this happens is because this ‘_this.’ command somehow applies to my main frame because that is where the function originates. So if anyone has any ideas that would be great. I understand that im probably making some very stupid mistake, but i am ok with that as long as i can get it to work. Thanks in advance. =)