NullReference Exception

Hi guys. I’m following a guide to make a 3d shooter, but I’m pretty stuck. I know there are other threads with almost exactly the same issue, but I really don’t understand those, so I hope you can help me.

The error:
NullReferenceException: Object reference not set to an instance of an object
Iron_man_movement.Move (Single h, Single v) (at Assets/ironman/Iron_man_movement.cs:33)
Iron_man_movement.FixedUpdate () (at Assets/ironman/Iron_man_movement.cs:25)

The Code:
using UnityEngine;
using System.Collections;
using UnitySampleAssets.CrossPlatformInput;

public class Iron_man_movement : MonoBehaviour {
Vector3 movement;
Rigidbody playerRigidBody;
// Use this for initialization
void Start () {

}

void awake () {
	playerRigidBody = GetComponent<Rigidbody> (); 
}

// Update is called once per frame
void Update () {

}
void FixedUpdate() {
	float h = CrossPlatformInputManager.GetAxisRaw ("Horizontal");
	float v = CrossPlatformInputManager.GetAxisRaw ("Vertical");

	Move (h, v); 
}

void Move (float h, float v){
	movement.Set (h, 0f, v);

	movement = movement.normalized * 5.0f;

	playerRigidBody.MovePosition(transform.position + movement);
}

}

playerRigidBody is null, because it never gets set.

awake() should be Awake(). Note the uppercase ‘A’

Also when pasting code, you should properly format it with the 101010 button so it’s clear to read.