这样修改了一下就不显示，麻烦帮我看一下哪里有问题？
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>JS随时练习</title>
</head>
<body id="body">
<script type="text/javascript">
function createa()
{
var abody=document.getElementById("body");
var ab=document.createElement("a");
ab.href="http://www.imooc.com";
ab.innerHTML="慕课网";
ab.style.color="red";
abody.appendChild(ab);
}
</script>
</body>
</html>
