Hello World Unity App - Simple Unity3d Button click and text updates

Work.cs

// Unity project here: https://www.dropbox.com/s/8nsuolthw2dzv4b/My%20Second%20Game%20Attempt.zip?dl=0

using UnityEngine;
using UnityEngine.UI;
using System.Collections;


public class Work : MonoBehaviour {

	public Text text;
	private int cash = 5;
	
	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
	}
	
	public void DoStuff () {
		cash++;
		text.text = "my cash = " + cash.ToString();
	}
}