When a user presses the submit button, the code placed in the onsubmit handler is executed before the form is submitted to the server.

当用户按下submit按钮时，在向服务器提交表单之前将执行onsubmit处理程序中的代码。

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When a user presses the submit button, the code placed in the onsubmit handler is executed before the form is submitted to the server.

当用户按下submit按钮时，在向服务器提交表单之前将执行onsubmit处理程序中的代码。

youdao