Unexpected token ")"

I have this script:

var WalkSpeedModifier : float = 8;
var WalkAnim : String = "Walk";
private var DefaultPos : Vector3;
private var Controller : CharacterController;
var PlayWhileAiming = false;
var obj = GameObject.Find("WalkAnim");
var anim = obj.GetComponent<Animation>();


function Start () {
	DefaultPos = transform.localPosition;
	Controller = GameObject.FindGameObjectsWithTag("Player").GetComponent(CharacterController);
}

function Update () {
	if (Input.GetAxis("Vertical")||Input.GetAxis("Horizontal")) {
		gameObject.animation.CrossFade(WalkAnim, 0.4);
		anim[WalkAnim].speed = Controller.velocity.magnitude / WalkSpeedModifier;
	}
	else {
		transform.localPosition = Vector3.Lerp(transform.localPosition, DefaultPos, 5);
		gameObject.animation.Stop(WalkAnim);
	}
	if (Input.GetButton("Fire2") && PlayWhileAiming == false) {
		transform.localPosition = Vector3.Lerp(transform.localPosition, DefaultPos, 5);
		gameObject.animation.Stop(WalkAnim);
	}
}

And it gives these errors:

Assets/Scripts/WalkAnimation.js(7,40): BCE0043: Unexpected token: ).
Assets/Scripts/WalkAnimation.js(7,41): BCE0044: expecting ), found ';'.
Assets/Scripts/WalkAnimation.js(7,42): UCE0001: ';' expected. Insert a semicolon at the end.

What am I doing wrong?

The following line uses a C# syntax and not a Javascript one

var anim = obj.GetComponent<Animation>();

See the documentation :

Taking a look at the documentation should be the first thing you do when you have an error !