Someone

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

namespace DoorsGame
{
    public partial class Form1 : Form
    {
        private int no_switch = 0;
        private int did_switch = 0;
        private int total_trials = 0;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            total_trials++;

            Random r = new Random();
            int door_chosen = r.Next(0, 3);
            int correct_door = r.Next(0, 3);
            if (correct_door == door_chosen)
            {
                no_switch++;
                listBox1.Items.Add("Win");
                listBox2.Items.Add("Loss");
            }
            else
            {
                did_switch++;
                listBox1.Items.Add("Loss");
                listBox2.Items.Add("Win");
            }

            lpDNS.Text = ((int)((no_switch * 100) / total_trials)).ToString() + "%";
            lpDS.Text = ((int)((did_switch * 100) / total_trials)).ToString() + "%";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            for (int i = 0; i < 1000; i++)
                button1_Click(sender, e);
        }
    }
}