Make A Laser?

I'm trying to make a laser for a weapon in a space ship game I'm making but not having much luck. I've tried using raycasts and a line renderer but then the line only shows when you hit something and I need it to show all the time. Does anyone have any ideas? I'm using unity free and JavaScript.

EDIT:

here is my script so far:

 #pragma strict
 
 var LRenderer : LineRenderer;
 
 
 function Start () {
     gameObject.AddComponent(LineRenderer);
     LRenderer = GetComponent(LineRenderer);
     LRenderer.SetPosition(0, transform.position);
     LRenderer.SetPosition(1, transform.position);
 
     LRenderer.SetColors(Color.blue, Color.white);
 }
 
 function Update () {
 
     var ray = new Ray (transform.position, transform.forward);
     var hit : RaycastHit;
     if(Input.GetKey(KeyCode.Space)){
         if(Physics.Raycast(ray, hit)){
             LRenderer.SetPosition(0, ray.origin);
             LRenderer.SetPosition(1, hit.point);
         }
     }
 }

The issue is I can figure out how to make the ray be drawn while shooting as well as when it hits. It this case the linerenderer only shows when the ray hits, and I want it to show while the ray is firing along the ray.