                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /JavaScript入門篇

請(qǐng)問各位我這里的代碼為啥除了改變顏色其他的都沒反應(yīng)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(wǎng)頁添加動(dòng)態(tài)效果并實(shí)現(xiàn)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(jìn)階篇，讓你掌握J(rèn)S的基礎(chǔ)語法、函數(shù)、數(shù)組、事件、內(nèi)置對(duì)象、BOM瀏覽器、DOM操作。</p>
??????? <p>3. 學(xué)完以上兩門基礎(chǔ)課后，在深入學(xué)習(xí)JavaScript的變量作用域、事件、對(duì)象、運(yùn)動(dòng)、cookie、正則表達(dá)式、ajax等課程。</p>
? </div>
? <form>
? 
??? <input type="button" value="改變顏色" onclick="changeColor()">?
??? <input type="button" value="改變寬高" onclic="cSize()">
??? <input type="button" value="隱藏內(nèi)容" onclic="displayText()">
??? <input type="button" value="顯示內(nèi)容" onclick="showText()">
??? <input type="button" value="取消設(shè)置" onclick="Canle()">
? </form>
? <script type="text/javascript">
? var c1;
? var c2;
? c1=document.getElementById("txt");
? c2=document.getElementById("con");
//定義"改變顏色"的函數(shù)
??? function changeColor(){
???????
???????
??????? c1.style.color="red";
??????? c1.style.backgroundColor="green";
???????
??????
??? }

//定義"改變寬高"的函數(shù)
??? function cSize(){
??????? c1=document.getElementById("txt");
???????
???????
??????? c1.style.width="100px";
??????? c1.style.height ="500px";
??? }

//定義"隱藏內(nèi)容"的函數(shù)
??? function displayText(){
??????? c1.style.display="none";
???
??? }

//定義"顯示內(nèi)容"的函數(shù)
??????? function showText(){
??????? c1.style.display="block";
???????
??? }

//定義"取消設(shè)置"的函數(shù)

??? function Canle(){
??????? var com=cobfirm("是否恢復(fù)原樣？");
??????? if(com==true){
??????????
??????????? c1.removeAttribute('style');
??????? }
??? }

? </script>
</body>
</html>