var   
  Form1: TForm1;   
  tserv: TTcpServer;   
  tclient:TTcpClient;   
  t: string;   
  
procedure TForm1.FormCreate(Sender: TObject);   
begin   
  tserv:=TTcpServer.Create(NIL);   
  tserv.LocalPort:='1111';   
  tserv.Active:=True;   
  begin   
    repeat   
    sleep(500);   
    t:=tserv.Receiveln();   
    if t='test' then   
      MessageBox(0, 'test', 'test',0);   
    until true   
  end;   
end;   
  
procedure TForm1.Button1Click(Sender: TObject);   
begin   
  tclient:=TTcpClient.Create(NIL);   
  tclient.RemoteHost:='127.0.0.1';   
  tclient.RemotePort:='1111';   
  tclient.Active:=True;   
end;   
  
procedure TForm1.Button2Click(Sender: TObject);   
begin   
  tclient.Sendln('test');   
end;