GetComponent error: Object Reference not set to an instance of an object.

So, I have this big block that is supposed to descend and crush the player when the player steps on a trigger. The console is returning the error "NullReferenceException: Object reference not set to an instance of an object. bigBlockTrigger.OnTriggerEnter(UnityEngine.Collider other)(at Assets/Scrips/bigBlockTrigger.js:19)"

Here are the two scripts (JAVASCRIPT):

(Code on trigger, "bigBlockTrigger")

 #pragma strict
 
 function Start () {
 
 }
 
 function Update () {
 
 }
 
 function OnTriggerEnter(other : Collider) {
     if(other.tag == "Player")
     {
     print("Woohoo");
     var Moving: bigBlockScript = GetComponent(bigBlockScript);
     Moving.isMoving = true;  
     }
 }

And (Code on Block, "bigBlockScript")

 #pragma strict
 
 public var isMoving : boolean = false;
 public var speed: int = 2;
 
 function Start () {
 
 }
 
 function Update () {
     if(isMoving == true){
         transform.position -= transform.up * speed * Time.deltaTime;
     }
 
 }

Please help :)!