<!DOCTYPE?html>
<html>
<head>
<meta?charset="utf-8">
<meta?http-equiv="X-UA-Compatible"?content="IE=Edge">
<meta?name="viewport"?content="width=device-width,?initial-scale=1">
<title>全球搜索,有問必應?(Bing)</title>
<style?type="text/css">
*{margin:?0;padding:?0;font-family:?"微軟雅黑";list-style:none;}
a:link{color:?lightgrey;}
a:hover{color:?white;}
body{background:?url(senlin.jpg)?fixed;background-position:center?center;overflow：hidden}
.nav{background-color:#444444;width:100%;height:45px;?}
.leftNav{margin-left:30px;}
.leftNav?a{text-decoration:?none;font-size:13px;float:?left;width:60px;height:45px;line-height:45px;list-style:none;text-align:center;}
.teshu?a{width:90px;float:?left;font-size:?12px;height:?45px;}
.logo{background:?url(logo.png);width:107px;height:?53px;float:?left;margin:120px??0??0?100px;}
.shuru{border:0;height:50px;line-height:50px;width:450px;font-color:?black;float:?left;margin:120px??0??0?15px;font-size:20px;}
.subMit{border:0;height:50px;line-height:50px;width:55px;font-color:?black;float:?left;background-image:url(search-button.jpg);margin:120px?0?0?0;}
.button1{width:50px;height:50px;float:?right;margin-right:?200px;margin-top:?500px;}
</style>
<body?id="main">
????<div>
????????<div>
????????????<ul>
????????????????<li><a?href="#">圖片</a></li>
????????????????<li><a?href="#">視頻</a></li>
????????????????<li><a?href="#">學術</a></li>
????????????????<li><a?href="#">詞典</a></li>
????????????????<li><a?href="#">地圖</a></li>
????????????????<li><a?href="#">更多</a></li>
????????????????<li><a?href="#">|</a></li>
????????????</ul>
????????????<ul>
????????????????<li><a?href="#">OfficeOnline</a></li>
????????????????<li><a?href="#">Outlook.com</a></li>
????????????</ul>
????????
????????</div>
????????
????????<div>
????????
????????</div>
????</div>
????<div>????
????</div>
????<form>
????????<input?type="text"></input>
????????<input?type="submit"?value=""></input>
????</form>
????<div>
????????<img??src="button1.png"?onclick="changeImage()"?>
????</div>
<!--下面是準備創建的函數-->
<script>
????function?changeImage()
????{
????var?n?=?Math.round((Math.random()*4));
????var?imgChange?=?document.getElementById("main");
????switch?(n)
????{
????????case?1:
????????imgChange.style.background?=?url("animals.jpg");
????????
????????case?2:
????????imgChange.style.background?=?url("cayuyuan.jpg");
????????break;
????????case?3:
????????imgChange.style.background?=?url("lake.jpg");
????????break;
????????case?4:
????????imgChange.style.background?=?url("gui.jpg");
????????break;
????????default:
????}????
}
</script>
</body>
創建一個函數，點擊頁面的左下角的按鈕可以更換body的背景圖片，可是一直無法實現，大神給看看
慕粉3398407
2016-05-26 18:38:53