<!DOCTYPE html>
<html>
<head>
<meta charset="{CHARSET}">
<title></title>
</head>
<body>
<span id="">語文成績：</span>
<input type="text" name="yuwen" id="yuwen" value="" />
<span id="">數(shù)學成績：</span>
<input type="text" name="shuxue" id="shuxue" value="" />
<span id="">英語成績：</span>
<input type="text" name="yingyu" id="yingyu" value="" />
<button id="btn">提交</button>
<script type="text/javascript">
var yuwen = document.getElementById('yuwen');
var shuxue = document.getElementById('shuxue');
var yingyu = document.getElementById('yingyu');
var btn = document.getElementById('btn');
document.getElementById("btn").onclick = function(){
if (yuwen.value >= 90 && shuxue.value >= 90 && yingyu.value >= 90) {
alert('獎勵一臺鋼琴');
// yuwen.value ="";
// shuxue.value ="";
// yingwu.value ="";
} else{
alert('給一巴掌');
}
}
</script>
</body>
</html>
