为什么document.write(a.id);不能显示？用alert也不行
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/JavaScript">
var a=document.getElementById("he");
document.write(a.id);
</script>
</head>
<body>
<div id="he"></div>
</body>
</html>相关分类