“Ctrl+/”
“F11/ESC”
<html>
<head>
<title>球体面积计算</title>
</head>
<body>
<script language="javascript">
<!--
radius = prompt("请输入球体的半径:");
area = 4 * Math.PI * Math.pow(radius, 2);
document.write("球体的面积为:" + area);
//-->
</script>
</body>
</html>