                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /焦點圖輪播特效

為什么我這代碼輪播圖死活都切換不了啊，js的代碼就沒一次打成功過

我不知道我為什么打js的代碼總是沒效果出來，明明瀏覽器js代碼沒有報錯，有也修復了，媽的就是死活不出效果。明明照著教程打永遠是這樣......

<!DOCTYPE html>
<html>
<head>
?<title>輪播圖</title>
?<meta charset="utf-8">
?<style type="text/css">
?? *{ margin: 0; padding: 0; text-decoration: none;}
?? body { padding: 20px;}
?? #container { width: 600px; height: 400px; border: 3px solid #333; overflow: hidden; position: relative;}
?? #list { width: 4200px; height: 400px; position: absolute; z-index: 1;}
?? #list img { float: left;}
?? #buttons { position: absolute; height: 10px; width: 100px; z-index: 2; bottom: 20px; left: 250px;}
?? #buttons span { cursor: pointer; float: left; border: 1px solid #fff; width: 10px; height: 10px; border-radius: 50%; background: #333; margin-right: 5px;}
?? #buttons .on {? background: orangered;}
?? .arrow { cursor: pointer; display: none; line-height: 39px; text-align: center; font-size: 36px; font-weight: bold; width: 40px; height: 40px;? position: absolute; z-index: 2; top: 180px; background-color: RGBA(0,0,0,.3); color: #fff;}
?? .arrow:hover { background-color: RGBA(0,0,0,.7);}
?? #container:hover .arrow { display: block;}
?? #prev { left: 20px;}
?? #next { right: 20px;}
?

?</style>
?<script type="text/javascript">
??widows.onload = function () {
????????? var container = document.getElementById('container');
??????????? var list = document.getElementById('list');
??????????? var buttons = document.getElementById('buttons').getElementsByTagName('span');
??????????? var prev = document.getElementById('prev');
??????????? var next = document.getElementById('next');

??????????? function animate (offset) {
??????????? ?list.style.left = parseInt(list.style.left) - offset + 'px';
??????????? }
???
???next.onclick = function () {
????animate(-600);
??????????? }
???????????
??????????? prev.onclick = function () {
??????????????? animate(600);

??????????? }

???
??}

?</script>

</head>
<body >
?<div id="container">
??? <div id="list" style="left: -600px;">
??????? <img src="img/5.jpg" alt="5"/>
??????? <img src="img/1.jpg" alt="1"/>
??????? <img src="img/2.jpg" alt="2"/>
??????? <img src="img/3.jpg" alt="3"/>
??????? <img src="img/4.jpg" alt="4"/>
??????? <img src="img/5.jpg" alt="5"/>
??????? <img src="img/1.jpg" alt="1"/>
??? </div>
??? <div id="buttons">
??????? <span index="1" class="on"></span>
??????? <span index="2"></span>
??????? <span index="3"></span>
??????? <span index="4"></span>
??????? <span index="5"></span>
??? </div>
??? <a href="javascripts:;" class="arrow" id="prev"><</a>
??? <a href="javascripts:;" class="arrow" id="next">></a>
</div>