how to get the userid of the user

static void Main(string[] args)

{

    Console.WriteLine("Current Logged UserName: " + Environment.UserName);
    Console.WriteLine("Local Machine Name: " + Environment.MachineName);
    Console.WriteLine("Local Machine Name: " + Dns.GetHostName()); 
    // Dns from System.Net

    // Console.WriteLine("IPHostEntry: " + Dns.GetHostByName(Dns.GetHostName)); 
    // Dns from System.Net

    IPHostEntry ip = Dns.GetHostEntry (Dns.GetHostName());
    IPAddress[] IPaddr = ip.AddressList;

    for (int i = 0; i < IPaddr.Length; i++)
        {Console.WriteLine("IP Address {0}: {1} ", i, IPaddr[i].ToString());}

    Console.ReadLine();

}