NullReferenceException Error: 2D Platformer: Move_Jump Script

Alright, so I’ve been trying to make a 2D Platformer in Unity. I’ve run into this error that just won’t go away and seems to halt the entire game, making it useless.

Here is my script. It says the error is on line 9. I will bold it out. Keep in mind, I am not an expert with Unity and I need an answer quick because this is a project for my Senior year of High School and I am using the latest version of Unity. (Unity 4.0)

var speed : float = 4.0;
var jumpspeed : float = 8.0;
var gravity : float = 20.0;

private var moveDirection : Vector3 = Vector3.zero;

function Update () {
var controller : CharacterController = GetComponent(CharacterController);

if (controller.isGrounded) {

moveDirection = Vector3(Input.getAxis(“Horizontal”), 0,0);
moveDirection = transform.TransformDirection(moveDirection);
moveDirection *= speed;

	if(Input.GetButton ("Jump")) {
	moveDirection.y = jumpspeed;
		}
	}
	moveDirection.y -= gravity * Time.deltatime;
	
	controller.Move(moveDirection * Time.deltatime);
}

It means that

var controller : CharacterController = GetComponent(CharacterController);

did not find CharacterController on the gameObject. Are you sure you attached CharacterController component?

No, I didn’t put a Character Controller on the object. In this case, I’ve been using a capsule.
This was the video I used to learn about the scripting.

Like I said, I’m no expert on this. I added a Character Controller to the capsule and the error still showed.