muzzle flash help

i made a muzzle flash, but i want it to "blink", how do i do that?

var Muzzle : GameObject;

function Start () {

Muzzle.active = false;

} function Update () {

 if(Input.GetButtonDown("Fire1")){
 animation.CrossFade("shoot");
 audio.Play();
 Muzzle.active = true;
 

} if(Input.GetButtonUp("Fire1")){ animation.CrossFade("idle"); audio.Pause(); Muzzle.active = false;

} }