                        課程
                    
                        /前端開發
                        
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                        /JavaScript入門篇

為什么點擊按鈕沒反應呢？

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" Content="text/html; charset=utf-8" />
<title>javascript</title>
<style type="text/css">
body{font-size:12px;}
#txt{
??? height:400px;
??? width:600px;
?border:#333 solid 1px;
?padding:5px;}
p{
?line-height:18px;
?text-indent:2em;}
</style>
</head>
<body>
? <h2 id="con">JavaScript課程</H2>
? <div id="txt">
???? <h5>JavaScript為網頁添加動態效果并實現與用戶交互的功能。</h5>
??????? <p>1. JavaScript入門篇，讓不懂JS的你，快速了解JS。</p>
??????? <p>2. JavaScript進階篇，讓你掌握JS的基礎語法、函數、數組、事件、內置對象、BOM瀏覽器、DOM操作。</p>
??????? <p>3. 學完以上兩門基礎課后，在深入學習JavaScript的變量作用域、事件、對象、運動、cookie、正則表達式、ajax等課程。</p>
? </div>
? <form>
? 
??? <input type="button" value="改變顏色" onclick="color()"/>?
??? <input type="button" value="改變寬高" onclick="wh()"/>
??? <input type="button" value="隱藏內容" onclick="non()"/>
??? <input type="button" value="顯示內容" onclick="blo()"/>
??? <input type="button" value="取消設置" onclick="r()"/>
? </form>
? <script type="text/javascript">
??? var con=document.getElementById("con");
??? var txt=document.getElementById("txt");

??? function color(){
??????? con.style.color="blue";
??????? txt.style.backgroundColor="#CCC";
??? }

??? function wh(){
??????? con.style.width="300px";
??????? txt.style.height="500px";
??? }

??? function non(){
??????? con.style.display="none";
??????? txt.style.display="none";
??? }

??? function blo(){
??????? con.style.display="block";
??????? txt.style.display="block";
??? }

??? function r(){
??????? var message=confirm("你確定要重置所有設置么？");
??????? if(message==true){
??????????? con.removeAttribute('style');
??????????? txt.removeAttribute('style');
??? }
? </script>
</body>
</html>