GUI doesn't show up.

using UnityEngine;
using System.Collections;

public class Gui : MonoBehaviour {

	// Use this for initialization
	void Start () {
	// Update is called once per frame
	void Update () {

	void OnGui() {

				GUI.Box(new Rect(10, 20, 160, 180), "Uselesness");



So I was watching a tutorial and did EXCACTLY what I was supposed to do. But the GUI dosent show up on the camera I have placed the script on.
So what have I done wrong?

So firstly it’s OnGUI not OnGui - you have to name it right with the correct capitals.

Secondly be sure this script is attached to a GameObject.