frameborder 属性规定是否显示框架周围的边框。
<!DOCTYPE html>
<html>
<body>
<iframe id="myframe" src="/default.asp" frameborder="0">
<p>Your browser does not support iframes.</p>
</iframe>
<p>The frameborder is set to:
<script>
document.write(document.getElementById("myframe").frameBorder);
</script>
<p>
</body>
</html>