C Sharp programs for Get DNS host and address informastion

The GetDNSHostInfo.cs program

using System;
using System.Net;
class GetDNSHostInfo
{
  public static void Main(string[] argv)
  {
   if (argv.Length != 1)
   {
    Console.WriteLine("Usage: GetDNSHostInfo hostname");
    return;
   }
   IPHostEntry results = Dns.GetHostByName(argv[0]);
   Console.WriteLine("Host name: {0}",
            results.HostName);
   foreach(string alias in results.Aliases)
   {
     Console.WriteLine("Alias: {0}", alias);
   }
   foreach(IPAddress address in results.AddressList)
   {
     Console.WriteLine("Address: {0}",
           address.ToString());
   }
  }
}

The GetDNSAddressInfo.cs program 
using System;
using System.Net;
class GetDNSAddressInfo
{
  public static void Main(string)[] argv)
  {
   if (argv.Length != 1)
   {
     Console.WriteLine("Usage: GetDNSAddressInfo address");
     return;
   }
   IPAddress test = IPAddress.Parse(argv[0]);
   IPHostEntry iphe = Dns.GetHostByAddress(test);
   Console.WriteLine("Information for {0}",
           test.ToString());
   Console.WriteLine("Host name: {0}", iphe.HostName);
   foreach(string alias in iphe.Aliases)
   {
     Console.WriteLine("Alias: {0}", alias);
   }
   foreach(IPAddress address in iphe.AddressList)
   {
     Console.WriteLine("Address: {0}", address.ToString());
   }
  }
}