how to stop particles from moving off stage, Actionscript random particle generator - actionscript-3

Question

Below is some code for a random particle generator. I want to change it so the particles only move a small distance before stopping and not disappearing. As it is now, they keep moving until they go off stage. I'm new to Actionscript so any help would be appreciated, thanks.
var particleArray:Array = new Array();
var maxParticles:Number = 50000;
function addParticle(e:Event)
{
var Symbol:Symbol3 = new Symbol3();
Symbol.alpha = Math.random() * .8 + .2;
Symbol.scaleX = Symbol.scaleY = Math.random() * .8 + .2;
Symbol.xMovement = Math.random() * 10 - 5;
Symbol.yMovement = Math.random() * 10 - 5;
Symbol.x = mouseX;
Symbol.y = mouseY;
particleArray.push(Symbol);
addChild(Symbol);
Symbol.cacheAsBitmap = true;
if (particleArray.length >= maxParticles)
{
removeChild(particleArray.shift());
}
Symbol.addEventListener(Event.ENTER_FRAME,moveParticle);
}
function moveParticle(e:Event)
{
e.currentTarget.x += e.currentTarget.xMovement;
e.currentTarget.y += e.currentTarget.yMovement;
}
var myTimer:Timer = new Timer(50);
myTimer.addEventListener(TimerEvent.TIMER, addParticle);
myTimer.start();

Answer 1

One way to do this would be to remove the event listener after a number executions:
function addParticle(e:Event)
{
var Symbol:Symbol3 = new Symbol3();
Symbol.alpha = Math.random() * .8 + .2;
Symbol.scaleX = Symbol.scaleY = Math.random() * .8 + .2;
Symbol.xMovement = Math.random() * 10 - 5;
Symbol.yMovement = Math.random() * 10 - 5;
// set the number of times this instance can move.
// Using a randomly generated number here
Symbol.movementCount = int(Math.random() * 10);
Symbol.x = mouseX;
Symbol.y = mouseY;
particleArray.push(Symbol);
addChild(Symbol);
Symbol.cacheAsBitmap = true;
if (particleArray.length >= maxParticles)
{
removeChild(particleArray.shift());
}
Symbol.addEventListener(Event.ENTER_FRAME,moveParticle);
}
function moveParticle(e:Event)
{
e.currentTarget.x += e.currentTarget.xMovement;
e.currentTarget.y += e.currentTarget.yMovement;
// decrement your move count, and then check to see if it's hit zero
e.currentTarget.movementCount--;
if(e.currentTarget.movementCount <=0)
{
// if so, remove the event listener
e.currentTarget.removeEventListener(Event.ENTER_FRAME, moveParticle);
}
}