<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>prompt</title>
<script type="text/javascript">
function rec(){
var sorce;
sorce=prompt("请输入你的成绩")；
if (sorce>=140)
{document.write("非常棒！")；}
if else(sorce>=120)
{document.write("很好")；}
if else(sorce>=90)
{document.write("加油哦")；}
else
{document.write("要努力了啊")；}
}
</script>
</head>
<body>
<input name="button" name="button" onClick="rec()" value="点击我，对成绩做评价!" />
</body>
</html>dommon