<html>
<head>
<script type="text/javascript"> function disp_alert() {
alert("我是警告框！！")
}
</script>
</head>
<body>
<input type="button" onclick="disp_alert()" value="显示警告框" />
</body>
</html>
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<html>
<head>
<script type="text/javascript"> function disp_alert() {
alert("再次向您问好！在这里，我们向您演示" + ‘\n‘ + "如何向警告框添加折行。")
} </script>
</head>
<body>
<input type="button" onclick="disp_alert()" value="显示警告框" />
</body>
</html>
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<html>
<head>
<script type="text/javascript"> function show_confirm()
{
var r=confirm("Press a button!");
if (r==true)
{
alert("You pressed OK!");
} else
{
alert("You pressed Cancel!");
}
} </script>
</head>
<body>
<input type="button" onclick="show_confirm()" value="Show a confirm box" />
</body> </html>
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<html>
<head>
<script type="text/javascript"> function disp_prompt()
{
var name=prompt("请输入您的名字","Bill Gates")
if (name!=null && name!="")
{ document.write("你好！" + name + " 今天过得怎么样？")
}
}
</script>
</head>
<body>
<input type="button" onclick="disp_prompt()" value="显示提示框" />
</body> </html>