W3School TIY
编辑您的代码：
<html> <head> <script type="text/javascript"> var txt="" function message() { try { adddlert("Welcome guest!") } catch(err) { txt="本页中存在错误。\n\n" txt+="点击“确定”继续查看本页，\n" txt+="点击“取消”返回首页。\n\n" if(!confirm(txt)) { document.location.href="../index.html"/*tpa=http://www.jb51.net/index.html*/ } } } </script> </head> <body> <input type="button" value="查看消息" onclick="message()" /> </body> </html>
查看结果: