Copy Listbox items to Clipboard

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;
using System.IO;

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


        private void Form1_Load(object sender, EventArgs e)
        {
            listBox1.Items.Add("Raj");
            listBox1.Items.Add("Ravi");
            listBox1.Items.Add("Rahul");
        }

        

        private void btn_copy_Click(object sender, EventArgs e)
        {
            string s1 = "";
            foreach (object item in listBox1.Items) s1 += item.ToString() + "\r\n";
            Clipboard.SetText(s1);
        }
    }
}