find the hostname for a known IP address

find the hostname for a known IP address with C Sharp

using System;
using System.Net;
class GetAddress
{
public static void Main(string[] argv)
{
if (argv.Length != 1)
{
Console.WriteLine("Usage: GetAddress 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());
}
}
}