void Start ()
    {
        anim = GetComponent<Animator> ();
        rb = GetComponent<Rigidbody2D> ();
        facingRight = true;
        speedX = 10;
        jumpSpeedY = 500;
    }

    void Update ()
    {
        MovePlayer(speed);

        if (Input.GetKeyDown(KeyCode.A))
        {
            speed = -speedX;
        }
        else if (Input.GetKeyUp(KeyCode.A))
        {
            speed = 0;
        }
        if (Input.GetKeyDown(KeyCode.D))
        {
            speed = speedX;
        }
        else if (Input.GetKeyUp(KeyCode.D))
        {
            speed = 0;
        }

        if (Input.GetKeyDown(KeyCode.Space))
        {
            Jumping = true;
            rb.AddForce(new Vector2(rb.velocity.x, jumpSpeedY));
        }
    }

    void MovePlayer(float playerSpeed)
    {
        rb.velocity = new Vector3(speed, rb.velocity.y, 0);
    }