Menu not appearing

Hello all. I am making a main menu for this new game I’m working on and I’ve encountered a weird outcome. I’ve been trying to create a menu that can scale depending on the res. I try to do this with the menuAreaNormalised var, but for some reason it doesn’t display anything. The area is completely empty where the buttons should appear.

using UnityEngine;
using System.Collections;

public class MainMenuGUI : MonoBehaviour {

	public GUISkin menuSkin;
	public Rect menuArea;
	public Rect playButton;
	public Rect instructionButton;
	public Rect quitButton;

	Rect menuAreaNormalised;

	void Start()
	{
		menuAreaNormalised = new Rect (menuArea.x * Screen.width - (menuArea.width * 0.5f), menuArea.y * Screen.height - (menuArea.height * 0.5f), menuArea.width, menuArea.height);	
	}

	void OnGUI()
	{
		GUI.skin = menuSkin;

		GUI.BeginGroup (menuAreaNormalised);

		if(GUI.Button(new Rect(playButton), "Play"))
		{

		}
		if(GUI.Button(new Rect(instructionButton), "Instructions"))
		{
			
		}
		if(GUI.Button(new Rect(quitButton), "Quit"))
		{
			
		}
		

		GUI.EndGroup ();
	}
}

playButton, instructionButton, quitButton are never assign any value so your buttons have size of zero.