编辑下面的代码:
【加编码】
查看效果 »
<html> <body> <button type="button" autofocus onclick="alert('Hello world!')">Click Me!</button> <p><strong>Note:</strong> The autofocus attribute of the button tag is not supported in IE 9 and earlier versions, or in Opera.</p> </body> </html>
结果:
【此窗口】
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