内容描述：用js代码实现点击按钮对div框架隐藏和显示，点击一次展开div,再次点击隐藏
代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
#div1 {
width: 100px;
height: 400px;
background-color: red;
display: none;
}
</style>
<script>
function f() {
var v1 = document.getElementById("div1");
if (v1.style.display == "none") {
v1.style.display = "block";
} else {
v1.style.display = "none";
}
}
</script>
</head>
<body>
<input type="button" value="显示隐藏" onclick="f()">
<div id="div1">
</div>
</body>
</html>效果图：
初始页
点击一次
点击两次
