Get enemy to fire at me from a high position

I am trying to get a enemy to fire at me from a watch tower however i do not know how to go about this. I have enemies on the ground that fire at me fine but I can seem to do this for the one on the watch tower. This is the code for the enemies who are firing at me on the ground-

// speed of the AI player public var speed:int = 4;

// speed the ai player rotates by public var rotationSpeed:int = 3;

// the waypoints public var waypoints:Transform[];

// current waypoint id private var waypointId:int = 0;

// the player private var player:GameObject;

// firing toggle private var firing:boolean = false;

// the Mesh Renderer of the Muzzle Flash GameObject private var muzzleFlash:GameObject;

/** Start */ function Start() { // retrieve the player player = GameObject.Find("First Person Controller");

 // retrieve the muzzle flash
 muzzleFlash = GameObject.Find("muzzleFlashAgent");
 
 // disable the muzzle flash renderer
 muzzleFlash.active = false;

}

/** Patrol around the waypoints */ function Patrol() { // if no waypoints have been assigned if (waypoints.Length == 0) { print("You need to assign some waypoints within the Inspector"); return; }

 // if distance to waypoint is less than 2 metres then start heading toward next waypoint
 if (Vector3.Distance(waypoints[waypointId].position, transform.position) < 2)
 {
     // increase waypoint id
     waypointId++;
     
     // make sure new waypointId isn't greater than number of waypoints
     // if it is then set waypointId to 0 to head towards first waypoint again
     if (waypointId >= waypoints.Length) waypointId = 0;
 }
 
 // move towards the current waypointId's position
 MoveTowards(waypoints[waypointId].position);

}

/** Move towards the targetPosition */ function MoveTowards(targetPosition:Vector3) { // calculate the direction var direction:Vector3 = targetPosition - transform.position;

 // rotate over time to face the target rotation - Quaternion.LookRotation(direction)
 transform.rotation = Quaternion.Slerp (transform.rotation, Quaternion.LookRotation(direction), rotationSpeed * Time.deltaTime);
 
 // set the x and z axis of rotation to 0 so the soldier stands upright (otherwise equals REALLY bad leaning)
 transform.eulerAngles = Vector3(0, transform.eulerAngles.y, 0);
 
 // use the CharacterController Component's SimpleMove(...) function
 // multiply the soldiers forward vector by the speed to move the AI
 GetComponent (CharacterController).SimpleMove(transform.forward * speed);
 
 // play the walking animation
 animation.Play("walk");

}

/** Update */ function Update() { // calculate the distance to the player var distanceToPlayer:int = Vector3.Distance(transform.position, player.transform.position);

 // calculate vector direction to the player
 var directionToPlayer:Vector3 = transform.position - player.transform.position;
 
 // calculate the angle between AI forward vector and direction toward player
 // we use Mathf.Abs to store the absolute value (i.e. always positive)
 var angle:int = Mathf.Abs(Vector3.Angle(transform.forward, directionToPlayer));
 
 // if player is within 30m and angle is greater than 130 (IN FRONT) then begin chasing the player
 if (distanceToPlayer < 30 && angle > 130)
 {
     // move towards the players position
     MoveTowards(player.transform.position);
     
     // if not firing then start firing!
     if (!firing) Fire();
 }
 // if player is within 5m and BEHIND then begin chasing
 else if (distanceToPlayer < 5 && angle < 130)
 {
     // move towards the players position
     MoveTowards(player.transform.position);
     
     // if not firing then start firing!
     if (!firing) Fire();
 }
 else
 {
     // patrol
     Patrol(); 
     
     // stop firing
     firing = false;
 }

}

/** Fire at the player */ function Fire() { // toggle firing on firing = true;

 // check if still firing
 while (firing)
 {
     // hit variable for RayCasting
     var hit:RaycastHit;
     
     // range of weapon
     var range:int = 30;
     
     // fire the ray from our position of our muzzle flash, forwards "range" metres and store whatever is detected in the variable "hit"
     if (Physics.Raycast(muzzleFlash.transform.position, transform.forward, hit, range)) 
     {
         // draw a line in the scene so we can see what's going on
            Debug.DrawLine (muzzleFlash.transform.position, hit.point);
         
         // if we hit the player
         if (hit.transform.name == "First Person Controller")
         {
             // inform the player that they have been shot
             player.GetComponent(PlayerShot).Shot();  
             
             // play gunshot sound
             audio.PlayOneShot(audio.clip); 
             
             // show muzzle flash for X seconds
             muzzleFlash.active = true;
             yield WaitForSeconds(0.05);
             muzzleFlash.active = false; 
             
             // wait a second or two before firing again
             yield WaitForSeconds(Random.Range(1.0, 2.0));
         }
     }
     
     // wait till next frame to test again
     yield;
 }

}