Yes I agree with the last too posters and I didn't realize your age. You're right, friendships at your age most of the time are very fickle. I know because my oldest daughter is 13 and I hear what goes on at school. You can be friends, then all of a sudden a disagreement happens and it's blows up. Then if you have facebook or another chat site, sometimes all the friends will start dissing the other one.

At this age, kids start to assert themselves and there's so much attitude floating around. In order to be resilient, you need to find a balance between being assertive or letting it role off you - not taking it too seriously. In the end if you're nice and act like a good friend, kids will be attracted to that. Best of luck.