start message

The wrong thing to do is to start a new message.

错误的做法是创建一封新邮件.

You start by creating a database table for the message board.

先为留言板创建一个数据库表。

If the start date is later than the end date, then the user receives an error message.

如果开始日期晚于结束日期，则用户会收到一条错误消息。

The message start event is implemented with an Undercover Agent ( UCA) as shown in Figure 4.

消息启动事件由一个Undercover Agent（UCA）实现，如图4中所示。

Generally, the handler will run its own postMessage() method to return a message to the calling code, and then the port's start() method generates an enable message process.

通常，这个处理程序会执行自己的postMessage（）方法将消息返回给调用代码，然后port的start（）方法就会生成一个启用消息过程。