Help with Unity's Parallax Scrolling Script Object reference not set to an instance of an object

Hello,

I was trying to use unity’s new Parallax Scrolling Script that they use in their 2d example project, but i get this error

NullReferenceException: Object reference not set to an instance of an object
BackgroundParallax.Awake () (at Assets/Tutorial/Scripts/BackgroundParallax.cs:18)

I use unityscript which may be why i cant solve this problem, could anyone help me out? Thanks

Here is the Parallax Scrolling Script made by unity

using UnityEngine;
using System.Collections;

public class BackgroundParallax : MonoBehaviour
{
	public Transform[] backgrounds;				// Array of all the backgrounds to be parallaxed.
	public float parallaxScale;					// The proportion of the camera's movement to move the backgrounds by.
	public float parallaxReductionFactor;		// How much less each successive layer should parallax.
	public float smoothing;						// How smooth the parallax effect should be.

	private Transform cam;						// Shorter reference to the main camera's transform.
	private Vector3 previousCamPos;				// The postion of the camera in the previous frame.


	void Awake ()
	{
		// Setting up the reference shortcut.
		cam = Camera.main.transform;
	}


	void Start ()
	{
		// The 'previous frame' had the current frame's camera position.
		previousCamPos = cam.position;
	}


	void Update ()
	{
		// The parallax is the opposite of the camera movement since the previous frame multiplied by the scale.
		float parallax = (previousCamPos.x - cam.position.x) * parallaxScale;

		// For each successive background...
		for(int i = 0; i < backgrounds.Length; i++)
		{
			// ... set a target x position which is their current position plus the parallax multiplied by the reduction.
			float backgroundTargetPosX = backgrounds_.position.x + parallax * (i * parallaxReductionFactor + 1);_
  •  	// Create a target position which is the background's current position but with it's target x position.*
    

Vector3 backgroundTargetPos = new Vector3(backgroundTargetPosX, backgrounds_.position.y, backgrounds*.position.z);*_

* // Lerp the background’s position between itself and it’s target position.*
backgrounds.position = Vector3.Lerp(backgrounds_.position, backgroundTargetPos, smoothing * Time.deltaTime);
* }*_

* // Set the previousCamPos to the camera’s position at the end of this frame.*
* previousCamPos = cam.position;*
* }*
}

You must have a camera in your scene, tagged “MainCamera” to use Camera.main.