                        课程
                    
                        /前端开发
                        
                            /JavaScript
                        
                        /JavaScript进阶篇

为何不显示呢

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style type="text/css">

.message{    
	width:200px;
	height:100px;
	background-color:#CCC;}
	
</style>
</head>
<body>
<script type="text/javascript">
var num=document.createElement("p");
num.className="message";
var numtext=document,createTextNode("I love javascript");
num.appendChild(numtext);
document.body.appendChild(num);


</script> 

</body>
</html>

为何不显示呢，哪出错了