Could anyone help me with this?

The main character of the game is a guy that you controll with the directional keys. You are supposed to go left and right to catch the balls that fall from the sky on your head, and you get a point. What I need help with is the balls falling script. I have a red ball, where the AS is written, and it has the instance name “ball”, and I have a yellow ball, and it’s instance name is “bad_ball”. The bad_ball doesn’t have any script in it. I want the yellow ball, to drop one random time in between 10 red ball. Please help me get the random yellow ball to work, and that there are more balls than one that can fall at the same time, because with this script, only one ball can fall, and when it disappears another one falls down.

Here’s the script.

onClipEvent (load) {
speed = 5;
_x = random(Stage.width);
_y = random(Stage.height);
}
 
onClipEvent (enterFrame) {
_y += speed;
if (_y>=400) {
_x = random(Stage.width);
_y = random(Stage.height)- 300;
}
}

I hope you understand anyting of what I asked about, because I think it might have been a little unclear. If so, just ask, and I’ll try to be more exact.

-Greatfaith-