How to display a series of images in a image control by a Button(Next)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace EgApp
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }


        private void Form1_Load(object sender, EventArgs e)
        {
            Img_idx = 0;
            pictureBox1.Image = imageList1.Images[Img_idx];
        }

        static int Img_idx;
        private void button2_Click(object sender, EventArgs e)
        {
            if (Img_idx < imageList1.Images.Count)
            {
                pictureBox1.Image = imageList1.Images[++Img_idx];
            }
        }


    }
}