用ASP.Net编写的查询域名的程序

下面是源程序。

<% @ Page Language="C#" %>
<% @ Assembly Name="System.Net" %>
<% @ Import Namespace="System.Net.Sockets" %>
<% @ Import Namespace="System.Text" %>
<% @ Import Namespace="System.IO" %>
<% @ Import Namespace="System.Collections" %>
<script language="C#" runat="server">
void doQuery(Object sender, EventArgs e)
{
  String strDomain = txtDomain.Text;
  char[] chSplit = {'.'};
  string[] arrDomain = strDomain.Split(chSplit);

  int nLength = arrDomain[1].Length ;
  Hashtable table = new Hashtable();
  table.Add("de", "whois.denic.de");
  table.Add("be", "whois.dns.be");
  table.Add("gov", "whois.nic.gov");
  table.Add("mil", "whois.nic.mil");

  String strServer ;         //define whois server
  //if the domainname's end is cn then the server is cnnic ,otherwise is networksolutions     
  if (arrDomain[arrDomain.Length - 1] == "cn")
    {
      strServer = "159.226.6.139" ;
    }    
  else
    {
      strServer = "whois.networksolutions.com";
    }  
    
  if (table.ContainsKey(arrDomain[1]))
  {
    strServer = table[arrDomain[1]].ToString();
  }
  else if (nLength == 2)
  {
    // 2-letter TLD's always default to RIPE in Europe
    strServer = "whois.ripe.net";
  }
  
  String strResponse;
  bool bSuccess = DoWhoisLookup(strDomain, strServer, out strResponse);
  if (bSuccess)
  {
    txtResult.Text = strResponse;
  }
  else
  {
    txtResult.Text = "Lookup failed";
  }
}

bool DoWhoisLookup(String strDomain, String strServer, out String strResponse)
{
  strResponse = "none";
  bool bSuccess = false;

  TCPClient tcpc = new TCPClient();
  if (0 == tcpc.Connect(strServer, 43))
  {
    strDomain += "\r\n";
    Byte[] arrDomain = Encoding.ASCII.GetBytes(strDomain.ToCharArray());
    try
    {
        String str;
Stream s = tcpc.GetStream();
        s.Write(arrDomain, 0, strDomain.Length);
    
        StreamReader sr = new StreamReader(tcpc.GetStream(), Encoding.Default);
        StringBuilder strBuilder = new StringBuilder();
        while (-1 != sr.Peek())
        {
          strBuilder.Append(sr.ReadLine()+"<br>");