NullReferenceException: Object reference not set to an instance of an object FPSAndroid.Update ()

hello , I was following a tutorial and I was having a few error and some how managed to fix them but now when I run the script I am getting

"NullReferenceException: Object reference not set to an instance of an object FPS_Android.Update () (at Assets/Scripts/FPS_Android.js:53) "

here is my script code :-

 @script RequireComponent(CharacterController)


 var moveTouchPad : Joystick;
 var rotateTouchPad : Joystick;

 var cameraPivot : Transform;//cam rotate//

 //Moving the Player on moving the Touch Pad//

 var forwardSpeed : float = 4;
 var backwardSpeed : float = 1;
 var sidestepSpeed : float = 1;
 var jumpSpeed : float = 8;
 var inAirMultiplier : float = 0.25; // Reduces Speed of running when u jump and run,used to      make it look more Realistic // 
 var rotationSpeed : Vector2 = Vector2( 50, 25 );
 var tiltPositiveYAxis : float = 0.6;
 var tiltNegativeYAxis : float = 0.4;
 var tiltXAxisMinimum : float = 0.1;

 private var thisTransform : Transform;
 private var character : CharacterController;
 private var cameraVelocity : Vector3;
 private var velocity : Vector3;
 private var canJump = true;

 function Start () {
 //THIS WILL DEFINE THE COMPONENTS TO SPEED UP LOADING TIME IN THE GAME //
 thisTransform = GetComponent(Transform);
 character = GetComponent(CharacterController);

 //MOVE THE CHARACTER TO THE SPAWN LOCATION IF IT EXISTS//        
 var spawn = GameObject.Find("PlayerSpawn");
 if(spawn){
     thisTransform.position = spawn.transform.position;
 
 }
 
 }

 function OnEndGame(){
 moveTouchPad.Disable();
 
 if(rotateTouchPad){
     rotateTouchPad.Disable();
 }
 
 this.enabled = false;
 }

 function Update () {
 
 var movement = thisTransform.TransformDirection(Vector3(moveTouchPad.position.x, 0 ,     moveTouchPad.position.y));
 movement.y = 0;
 movement.Normalize();
 
 var absJoyPos =     Vector2(Mathf.Abs(moveTouchPad.position.x),Mathf.Abs(moveTouchPad.position.y)); 
 
 if(absJoyPos.y > absJoyPos.x){
     
     if(moveTouchPad.position.y > 0){
         movement *= forwardSpeed * absJoyPos.y;
     }
     else{
         movement *= backwardSpeed * absJoyPos.y;
     }
 }
 else{
     movement *= sidestepSpeed * absJoyPos.y;
 
 }
 
 if(character.isGrounded){
 var Jump = false;
 var touchPad : Joystick;
 
     if(rotateTouchPad){
         touchPad = rotateTouchPad;
     }
     
     else{
          touchPad = moveTouchPad;
     } 
      
     if(!touchPad.IsFingerDown()){
          canJump = true;
     }
      
     if( canJump && touchPad.tapCount >= 2){
          velocity = character.velocity;
          
          velocity.y = jumpSpeed;    
     }
     
     else{
         velocity.y += Physics.gravity.y * Time.deltaTime;
         
         movement.x *= inAirMultiplier;
         movement.z *= inAirMultiplier;
     }
     
     movement += velocity;
     movement += Physics.gravity;
     movement *= Time.deltaTime;
      
     character.Move(movement);
     
      if(character.isGrounded){
          var camRotation = Vector2.zero;
          
          if(rotateTouchPad){
              camRotation = rotateTouchPad.position;
          }
          
          else{
              print(iPhoneInput.acceleration);
                  var acceleration = Input.acceleration;
                  var absTiltX = Mathf.Abs(acceleration.x);
                  
                  if(acceleration.z < 0 && acceleration.x <0){
                      
                      if(absTiltX >= tiltPositiveYAxis){
                          camRotation.y = (absTiltX -  tiltPositiveYAxis) / (1 - tiltPositiveYAxis);
                      }
                      
                      else if(absTiltX <= tiltNegativeYAxis){
                          camRotation.y = -(tiltNegativeYAxis - absTiltX) / tiltNegativeYAxis;
                      }
                  }
                  
                  if(Mathf.Abs(acceleration.y) >= tiltXAxisMinimum){
                      camRotation.y = -(acceleration.y - tiltXAxisMinimum) / (1 - tiltXAxisMinimum);
                  }
                  
                  camRotation.x *= rotationSpeed.x;
                  camRotation.y *= rotationSpeed.y;
                  camRotation *= Time.deltaTime;
                  
                  thisTransform.Rotate(0, camRotation.x,0,Space.World);
                  
                  cameraPivot.Rotate (-camRotation.y , 0 , 0);
                  
                  }
     }
 }  
 }

Thanks!