Particle on and off

Hi, I have a chest that opens and closes with OnTrigger , I would put a particle emitter in the chest, and just turn it on when the chest is opened. Here is the script I’m using, I would like someone help him. Thank you.

var AngleX : float = 0.0;    
var AngleY : float = 0.0;    
var AngleZ : float = 0.0;  

private var targetValue : float = 0.0;    
private var currentValue : float = 0.0;    
private var easing : float = 0.1;  

var Target : GameObject

function Update () {    
	currentValue = currentValue + (targetValue - currentValue) * easing;

	Target.transform.rotation = Quaternion.identity;    
	Target.transform.Rotate (0 , 0, currentValue);	    
}

function OnTriggerEnter (other : Collider) {        
	targetValue = AngleX;    
	currentValue = 0.0;    
}

function OnTriggerExit (other : Collider) {    
	currentValue = AngleX;    
	targetValue = 0.0;    
}

Shuriken or legacy.