Waypoint NullReferenceException: Object reference not set to an instance of an object error please help.

ok i keep getting this error but i have no idea how to fix it. Please help. :)

i basically have 3 script. One is the waypoint script, second is a player script and enemy script. Player script have a function call FindClosestEnemy to find the closest waypoint around the player. Then it store the name in to the static var closestpos:GameObject. After this i want in my WAYPOINT script var closest = playerscript.closestpos. And caculate by if/else function weather the waypoint.transform.position.z is smaller or bigger than the closestpos.transform.position. if yes do sth...if no do sth...etc.

i able to make it work in game scene, but it just keep poping up this error in my console. Can someone help me please. /bow

MY PLAYER SCRIPT

static var closestpos: GameObject;

function Update()

{

FindClosestEnemy();

}

function FindClosestEnemy () : GameObject {

// Find all game objects with tag Enemy

var waypoint : GameObject[];

waypoint = GameObject.FindGameObjectsWithTag("waypoint");

var closest : GameObject;

var distance = Mathf.Infinity;

var position = transform.position;

for (var closestwaypoint : GameObject in waypoint) {

 var diff = (closestwaypoint.transform.position - position);

 var curDistance = diff.sqrMagnitude; 

 if (curDistance < distance) { 

     closest = closestwaypoint; 

     distance = curDistance; 

     closestpos = closest;


 } 

} return closest;


}

MY WAYPOINT SCRIPT

var waypoint : Transform[];

private var currentWaypoint: int;

var player : Transform;

var saveTime = 0;

private var closest: GameObject;

function Update()

{

Debug.Log(playerscript.closestpos.transform.position);

closest = playerscript.closestpos;

var position = transform.position;

if(transform.position.z < closest.transform.position.z)

//NullReferenceException: Object reference not set to an instance of an object waypoint.Update () (at Assets/scripts/waypoint.js:15)

{ currentWaypoint=1;

} else {

if(transform.position.z > closest.transform.position.z)

{ currentWaypoint=0;

} else {

if(transform.position.x > closest.transform.position.x)

{

currentWaypoint=2;

} else {

if(transform.position.x < closest.transform.position.x)

{

currentWaypoint=3; } } } } }

function OnTriggerEnter (enemy : Collider) {

if (enemy.gameObject.tag == "enemy")

{

var rotation = waypoint[currentWaypoint].rotation;

var position = waypoint[currentWaypoint].position;

enemy.transform.LookAt(position);

}

}