Timed particle system disable

Forgive me but this is my first post.

I have been trying to turn off a particle system by using waitforseconds after it has been activated by gui but instead the script disables the button

Here is the script i am trying to use on an empty that is supposed to wait and ultimately stop particle system like a reset or so

var water : GameObject;

function Start(){

 water.active = true;
  

}

function Update(){

 if (water.active);
 WaitForSeconds (8);
 
 water.active = false;

}

I have also tried it on the actual water game object with the same result