private bool ValidateServerBox()
        {
            string server = txtServer.Text;

            if (string.IsNullOrWhiteSpace(server))
            {
                ServerIsValid = null;
                return(false);
            }

            if (AddressBookEntry.IsValidServerEntry(server))
            {
                ServerIsValid = true;
                return(true);
            }

            ServerIsValid = false;
            return(false);
        }
        public AddressBookWindow(string currentServer, string currentPort)
            : this()
        {
            if (!string.IsNullOrWhiteSpace(currentServer) && !string.IsNullOrWhiteSpace(currentPort))
            {
                string toCheck = string.Format("{0}:{1}", currentServer, currentPort);
                if (AddressBookEntry.IsValidServerEntry(toCheck))
                {
                    var existing = FindMatchingEntry(toCheck);
                    if (existing != null)
                    {
                        txtName.Text   = existing.Name;
                        txtServer.Text = existing.Address;
                    }
                    else
                    {
                        txtServer.Text = toCheck;
                    }

                    txtName.Focus();
                }
            }
        }