Collision Detection is very important to the Flash!
Now , i have been making a game about basketball,but there is a big skill problem blocked my game development which is about the collision detection algorithm of two balls.
I have defined the name "ball" and "balll".They are all from Ball Class.Ball Class have got the Attribute ,such as ball.vx,ball.vy,ball.radius,ball.v;

Here is my code

sina = (ball.y - balll.y)/(ball.radius + balll.radius);
cosa = (ball.x - balll.x)/(ball.radius + balll.radius);
distance = Math.sqrt((ball.x - balll.x)*(ball.x - balll.x) +(ball.y - balll.y)*(ball.y - balll.y));
if (distance <= (ball.radius +balll.radius))
{
v = Math.sqrt(ball.vx * balll.vx + ball.vy * balll.vy);
ball.x = balll.x+cosa*(ball.radius+balll.radius);
ball.y = balll.y+sina*(ball.radius+balll.radius);
ball.vy *= 0.8;
ball.vx *= 0.4;
ball.vx = (v * cosa);
ball.vy = (v * sina);
balll.vx = -(v * cosa);
balll.vy = -(v * sina);
}
Now , if the speed of ball is so fast , two ball will l overlapped together and they will not move or move slowly.How can i solve this problem?