public static bool PingHost(string nameOrAddress)
        {
            bool pingable = false;
            System.Net.NetworkInformation.Ping pinger = null;

            try
            {
                pinger = new System.Net.NetworkInformation.Ping();
                System.Net.NetworkInformation.PingReply reply = pinger.Send(nameOrAddress, 100);
                pingable = reply.Status == System.Net.NetworkInformation.IPStatus.Success;
            }
            catch (System.Net.NetworkInformation.PingException)
            {
                // Discard PingExceptions and return false;
            }
            finally
            {
                if (pinger != null)
                {
                    pinger.Dispose();
                }
            }
            return pingable;
        }