variables across scripts and across gameObjects

ok i have a problem i want to send some information from one script that is a attached to game object A to game object B's script. i am trying to get these to objects to look at game object C. its all compiling and stuff but then gives me this error: NullReferenceException: Object reference not set to an instance of an object LookAt.Update () (at Assets/Scripts/LookAt.js:13) i dont understand why, but here are my scripts attach to each objects. GameObject A's Script: attackRTriggerStay.JS

 @HideInInspector 
var targetAquired = false;
var attackTarget; 
function OnTriggerEnter (other : Collider) {
	print(targetAquired);
	if(other.gameObject.CompareTag ("enemy")){
		attackTarget = other.transform;
		targetAquired = true;
		print("targetAquired");
	}
}
function OnTriggerExit (other : Collider) {
if(other.gameObject.CompareTag ("enemy")){
		targetAquired = false;
		print(targetAquired);
	}
}

Game Object B's Script: LookAt.JS

    var getChildTrue : attackRTriggerStay;
    var getChildTarget : attackRTriggerStay;
    function start(){
        getChildTrue = GetComponentInChildren(attackRTriggerStay);
        getChildTarget = GetComponentInChildren(attackRTriggerStay);
    }
    function Update () {
    	if(getChildTrue.targetAquired == true){
    		transform.LookAt(getChildTarget.attackTarget); //.attackTarget is GameObject C
        }
    }