怎么<span>没有当作字符串输出
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>document.getElementById</title>
</head>
<body>
<p id="con"><span>JavaScript</span></p>
<script type="text/javascript">
var mychar=document.getElementById("con") ;
document.write("结果:"+mychar.innerHTML); //输出获取的P标签。
</script>
</body>
</html>
