<iframe src="http://www.youdao.com" width="500" height="600" ></iframe>
属性：
frameborder 1 0指定是否有无边框
scrolling： auto|yes|no specifies whether or not to display scrollbars in an <iframe>.
Use iframe as a Target for a Link
An iframe can be used as the target frame for a link.
The target attribute of a link must refer to the name attribute of the iframe:
<iframe src="demo_iframe.htm" name="iframe_a"></iframe>
<p><a href="http://www.w3schools.com" target="iframe_a">W3Schools.com</a></p>
深入参考：