function Update ()     
 {    
    if (Input.GetMouseButton (0))     
      {    
         var ray = Camera.main.ScreenPointToRay (Input.mousePosition);    
        var hit : RaycastHit;    
         if (Physics.Raycast (ray, hit))     
         {    
             Debug.DrawLine (ray.origin, hit.point);    
             print(hit.collider.gameObject.name);    
        }    
     }    
 }