my player is not going up on click or pressing space bar ?

bool didFlap = false;

// Use this for initialization
void Start () {
	 
}

void update() {
	if (Input.GetKeyDown(KeyCode.Space) || Input.GetMouseButtonDown(0)) {
		didFlap = true;
	}
}
// Update is called once per frame
void FixedUpdate () {
	velocity += gravity  * Time.deltaTime;

	if (didFlap == true) {
		didFlap = false;
		velocity += flapVelocity;
	}
    
		velocity = Vector3.ClampMagnitude (velocity, maxSpeed);

	transform.position += velocity * Time.deltaTime;
	
}

}

Capitalize Update()