If it fails validation, you will display an error message to the user.

如果验证失败，您需要向用户显示一条错误消息。

youdao

Show an error message if the user id or password is invalid.

如果用户ID或者密码无效则显示一条出错信息。

youdao

Although it'll show a message to the user, this could be done better.

尽管它将向用户显示一条消息，但是可以做得更好。

youdao

OneLeap, a UK-based company, enables any user to send a message to any other user within the OneLeap system for a fee.

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When the worm infects a computer it sends out the "lol" message to the user's contact list.

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Once the fake applications were downloaded, the virus sent a text message without the user's knowledge to a premium-rate number he had set up.

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