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                        /JavaScript入門篇

求分析看不大懂

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>className屬性</title>
<style>
??? body{ font-size:16px;}
??? .one{
??border:1px solid #eee;
??width:230px;
??height:50px;
??background:#ccc;
??color:red;
??? }
?.two{
??border:1px solid #ccc;
??width:230px;
??height:50px;
??background:#9CF;
??color:blue;
?}
?</style>
</head>
<body>
??? <p id="p1" > JavaScript使網(wǎng)頁顯示動態(tài)效果并實現(xiàn)與用戶交互功能。</p>
??? <input type="button" value="添加樣式" onclick="add()"/>
?<p id="p2" class="one">JavaScript使網(wǎng)頁顯示動態(tài)效果并實現(xiàn)與用戶交互功能。</p>
??? <input type="button" value="更改外觀" onclick="modify()"/>

?<script type="text/javascript">
??? function add(){
?????? var p1 = document.getElementById("p1");
??????
??? }
??? function modify(){
?????? var p2 = document.getElementById("p2");
??????
??? }
?????? p1.className ="two"
?????? p2.className="one"
?</script>
</body>
</html>