Making Random Graphic Generator Into A Class?

I have created some code that creates a blue circle of random size on the stage, and startmoving it in a random direction, at a random speed.

But I'd like to create this as a static class, so that I can just import into a banner and make multiple instances appear at a time, but my limited knowledge doesn't allow me to

Here is my code:

Code:

var child:Shape = new Shape()
var childSpeedX:Number = Math.random()
var childSpeedY:Number = Math.random()
var childDirectionX:Number = Math.random()

[Code]....