<html>
<head>
<title>多重选取（if）</title>
</head>
<body>
<script language="javascript">
<!--
souce = prompt("请输入您的成绩:");
document.write("您的成绩为:",souce,"<br>");
if(souce >= 90){
document.write("等级为 A")
}else if(souce >= 80){
document.write("等级为 B")
}else if(souce >= 60){
document.write("等级为 C")
}else{
document.write("等级为 D")
}
//-->
</script>
</body>
</html>