关于多线程的问题，线程是不是死锁了？

C# code

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Net;using System.Windows.Forms;using System.Text.RegularExpressions;using System.Threading;namespace WindowsFormsApplication1{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void Form1_Load(object sender, EventArgs e)        {            textBox1.Text = "www.baidu.com";        }        private void button1_Click(object sender, EventArgs e)        {            Thread[] thraed = new Thread[5];            ThreadStart start = new ThreadStart(Download);            for (int i = 0; i < 5; ++i)            {                thraed[i] = new Thread(start);                thraed[i].Start();            }                    }        public string[] GetSiteInfo(string uri)        {            string[] info = new string[5];            info[0] = uri;          //保存域名            info[1] = GetIP(uri);   //保存IP            info[2] = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");            if (!Regex.IsMatch(uri, "http://", RegexOptions.IgnoreCase))            {                uri = "http://" + uri;            }            double timeStart  = System.Environment.TickCount;   //获取系统开机到现在的时间            HttpWebRequest hw = (HttpWebRequest)WebRequest.Create(uri);            try            {                WebResponse wr = hw.GetResponse();                double timeEnd = System.Environment.TickCount;  //获取系统开机到现在的时间                double dTime = (timeEnd - timeStart) / 1000;    //计算网站的访问速度                string time = dTime.ToString() + " 秒";                info[3] = time;                info[4] = "true";            }            catch (Exception e)            {                info[3] = e.Message;                info[4] = "false";            }            return info;        }        public string GetIP(string hostName)        {            IPHostEntry ipHost = Dns.GetHostEntry(hostName);            return ipHost.AddressList[0].ToString();        }        private delegate void input();                private void Download()        {            while (true)            {                Thread.Sleep(100);                                            textBox2.BeginInvoke(new input(show));            }        }        private void show()        {                      string[] info = new string[4];            info = GetSiteInfo(textBox1.Text.Trim());            textBox2.AppendText("域名：" + info[0] + "\r\nIP：" + info[1] + "\r\n访问时间：" + info[2] + "\r\n响应速度：" + info[3] + "\r\n\r\n");        }    }}

各位走过路过的大大们看看，上面的代码是不是发生死锁了？
我对多线程的知识不是很了解，调试了几个小时了，还是没找到原因
点击button1控件运行时，textBox2控件就显示下载了两次，然后程序就不幸身亡
蛋疼啊，各位大大看看到底哪出问题了，小弟在此谢过

[解决办法]
你还丢了很重要一句

WebResponse wr = hw.GetResponse();
double timeEnd = System.Environment.TickCount; //获取系统开机到现在的时间
double dTime = (timeEnd - timeStart) / 1000; //计算网站的访问速度
string time = dTime.ToString() + " 秒";
info[3] = time;
info[4] = "true";
wr.Close();
[解决办法]

你的多线程异步给处理方法的时候 只要起到传递和分配作用就好

其他的不用管