利用udp實作小聊天室。 多個用戶可同時上線並一同聊天，用戶可自行更改名字，並選擇與所有用戶聊天或私訊某一用戶-Use udp implement small chat rooms. Multiple users can simultaneously chat on line and together, users can change their own name, and choose all users chat or private information to a user