Welcome to WebmasterWorld Guest from 188.8.131.52
Look at some HTML reference guides on the web for more info on <FRAME> or <IFRAME> tags, and their usage.
<p>If you are reading this message, that means your browser does not support the inline frame element. <a href="http://www.example.com/">Click here to access the document, thank you.</a></p>
In the above example, I am controlling all visual aspects of the <iframe> through my external CSS. What's nice about this method is that I can "float" the <iframe> in the center of the page and provide a top navigation element and bottom navigation element.
Using the <iframe> will present a scrollbar to the user in the center of the page (or wherever the <iframe> is positioned), which I've observed some users are still a little unfamiliar with.
P.S. Everything between the <iframe></iframe> is the area that get's indexed by the spiders. You can literally drop an entire page of structured content in there as that is what users will see that don't have <iframe> support (which is mostly bots). ;)