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                        /JavaScript入門篇

為什么高寬沒有辦法改變,點了之后什么都沒有發(fā)生

<!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:black?solid?3px;
????????????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)頁添加動態(tài)效果并實現(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進階篇，讓你掌握JS的基礎語法、函數(shù)、數(shù)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>
????<!--當點擊相應按鈕，執(zhí)行相應操作，為按鈕添加相應事件-->
????<input?type="button"?value="改變顏色"?onclick??=?"color()">
????<input?type="button"?value="改變寬高"?onclick?=?"size()">
????<input?type="button"?value="隱藏內容"?onclick??=?"hide()">
????<input?type="button"?value="顯示內容"?onclick??="show()">
????<input?type="button"?value="取消設置"?onclick??="cancel()">
</form>
<script?type="text/javascript">
????//定義"改變顏色"的函數(shù)
????function?color(){
????????var?txt?=???document.getElementById("txt");
????????txt.style.color?=?"red";
????????txt.style.backgroundColor?=?"blue";
????}

????//定義"改變寬高"的函數(shù)
????function?size(){
????????var?txt?=??document.getElementById("txt");
????????txt.style.width?=?"500px";
????????txt.style.height?=?"300px";

????}

????//定義"隱藏內容"的函數(shù)
????function?hide(){
????????var?txt?=??document.getElementById("txt");
????????txt.style.display?=?"none";
????}

????//定義"顯示內容"的函數(shù)
????function?show(){
????????var?txt?=???document.getElementById("txt");
????????txt.style.display?=?"block";

????}

????//定義"取消設置"的函數(shù)
????function?cancel(){
????????var?confirm?=?window.confirm("混蛋真的不改了嗎?");
????????var?txt?=???document.getElementById("txt");
????????if(confirm?==?true){
????????????txt.style?=?"none";
????????}

????}



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