Animation not Switching

Unity Engine
1 
var speed : float;
var deviation : float;
private var animator : Animator;

function Start () {

	rigidbody2D.velocity.x = speed;
}

function OnCollisionEnter2D (other : Collision2D) {

	if(other.gameObject.tag == "Player"){
		
		rigidbody2D.velocity.x = -speed;
		rigidbody2D.velocity.y = Random.Range(-deviation, deviation);
		StartCoroutine("Hit", 0);
	}
	
	if(other.gameObject.tag == "AI"){
	
		rigidbody2D.velocity.x = speed;
		rigidbody2D.velocity.y = Random.Range(-deviation, deviation);
		StartCoroutine("Hit", 0);
	}
	
	if(other.gameObject.tag == "Top Wall"){
	
		rigidbody2D.velocity.y = Random.Range(0, -deviation);	
	}
	
	if(other.gameObject.tag == "Bottom Wall"){
	
		rigidbody2D.velocity.y = Random.Range(0, deviation);	
	}
	
	if(other.gameObject.tag == "Restart"){
	
		Application.LoadLevel(0);
	}
}

function Hit () {

	animator.SetBool("Hit", true);
	yield WaitForSeconds(.25);
	animator.SetBool("Hit", false);
}

Returns NullReferenceException due to this function.

function Hit () {

	animator.SetBool("Hit", true);
	yield WaitForSeconds(.25);
	animator.SetBool("Hit", false);
}

Though, I do not know why. Help?

2

Your animator wasn’t set, only declared. Therefore, it will remain null.