Получение html кода страницы в listbox - C#

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.Net;
using System.IO;
using System.Text.RegularExpressions;
 
namespace Ужас2
{
    public partial class Form1 : Form
    {
        List<string> stroki = new List<string>();
        public Form1()
        {
            InitializeComponent();
        }
 
        public string GetHtmlPageText(string url)
        {
            string txt = String.Empty;
            WebRequest req = WebRequest.Create(url);
            WebResponse resp = req.GetResponse();
            using (Stream stream = resp.GetResponseStream())
            {
                using (StreamReader sr = new StreamReader(stream))
                {
                    txt = sr.ReadToEnd();
                }
            }
 
            return txt;
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
            string s = GetHtmlPageText("http://www.techweek.ru/poluchit-soderzhimoe-fajla-iz-internet/");
            textBox1.Text = s;
        }
    }
}