下拉列表的了解
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
#box {
width: 100px;
height: 100px;
background: pink;
margin: 20px 80px;
}
</style>
</head>
<body>
<div id="box"></div>
<input type="button" value="变宽" onclick="aa()">
<input type="button" value="变高" 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()">
<script type="text/javascript">
var box
window.onload = function() {
box = document.getElementById('box')
}
function aa() {
box.style.width = "400px;"
}
function bb() {
box.style.height = "400px;"
}
function cc() {
box.style.background = "blue"
}
function dd() {
box.style.height = "100px"
box.style.width = "100px"
box.style.background = "pink"
}
function ee() {
box.style.display = "none"
}
function ff() {
box.style.display = "block"
}
</script>
</body>
</html>