第一个div案例
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>changeDIV</title>
<style type="text/css">
#box{width: 100px;height: 100px;background: blue;margin: 20px 80px;}
</style>
</head>
<body>
<script type="text/javascript">
var box
window.onload=function () {
box=document.getElementById('box')
}
function aa() {
box.style.height="300px"
}
function bb() {
box.style.width="300px"
}
function cc() {
box.style.background="pink"
}
function dd() {
box.style.height="100px"
box.style.width="100px"
box.style.background="red"
}
function ee() {
box.style.display="none"
}
function ff() {
box.style.display="block"
}
</script>
<div id="box"></div>
<input type="button" value="变高" onclick="aa()">
<input type="button" value="变宽" onclick="bb()">
<input type="button" value="变色" onclick="cc()">
<input type="button" value="重置" onclick="dd()">
<input type="button" value="隐藏" onclick="ee()">
<input type="button" value="显示" onclick="ff()">
</body>
</html>