                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /JavaScript入門篇

有人能幫忙看下為什么我的代碼運行不起來嗎?多謝了！

<!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" onclick="ChangeColor()" value="改變顏色"> ?
??? <input type="button" onclick="ChangeWH()" value="改變寬高">
??? <input type="button" onclick="ContentHidden()" value="隱藏內容">
??? <input type="button" onclick="ContentDisplay()" value="顯示內容">
??? <input type="button" onclick="ResetToDefault()" value="取消設置">
? </form>
? <script type="text/javascript">
//定義"改變顏色"的函數
??? function ChangeColor(){
?????? var mychar1 = document.getElementById("con");
?????? mychar1.style.color="blue";???? ?
?????? var mychar2 = document.getElementById("txt");
?????? mychar2.style.color="blue";?? ? ?
??? }
//定義"改變寬高"的函數
??? function ChangeWH(){
?????? var mychar1 = document.getElementById("con");
?????? mychar1.style.width="800";
?????? mychar1.style.height="200";?? ?? ?
?????? var mychar2 = document.getElementById("txt");
?????? mychar2.style.width="800";
?????? mychar2.style.height="200";
??? }
//定義"隱藏內容"的函數
??? function ContentHidden(){
?? ??? var mychar1 = document.getElementById("con");
?????? mychar1.style.display="none";?? ? ?
?????? var mychar2 = document.getElementById("txt");
?????? mychar2.style.display="none";
??? }
//定義"顯示內容"的函數
??? function ContentDisplay(){
?? ??? var mychar1 = document.getElementById("con");
?????? mychar1.style.display="block";?? ? ?
?????? var mychar2 = document.getElementById("txt");
?????? mychar2.style.display="block";
??? }

//定義"取消設置"的函數
??? function ResetToDefault(){
?? ?var mymessage=confirm("Are you sure you want to reset all settings to default");
?? ?if(mymessage==true)
?? ?{
?? ???? var mychar1 = document.getElementById("con");
?? ??? ?var mychar2 = document.getElementById("txt");
??????? mychar2.style.color = "black";
??????? mychar2.style.backgroundColor = "white";
??????? mychar2.style.width = orignWidth;
??????? mychar2.style.height = orignHeight;
??????? mychar2.style.display = "block";
?? ?}
?? ?else
??? }
? </script>
</body>
</html>