Iframes/Frames are an easy tool for webmasters to use. They allow you to load only part of a page (the content stuff) while keeping the layout already loaded. This also allows for a really easy layout change. Some webmasters don't like to use them, especially if they have access to more advanced coding, such as PHP includes, but for the simple webmaster, iframes are a wonderful tool.
The Basic Code
Every frame/iframe will start out with this basic code.
<center>
<iframe name="iframe" src="home.html"
frameborder="0" width="###" height="###">
</iframe>
</center>
So your basic code goes into your "content" area where you want your page to load. You just need to match the width="###" to your layout space. For example, if my table layout has 500px in the area for a width, then I would make it say width="500". For the height, you just choose the height you'd like to have. I would choose something fairly long but not ridiculously long. I normally go for 600px or more. Anything smaller would get annoying.
The frameborder="0" makes it so you don't have a weird line around the frame area so it is a better flow. You can add one however if you so choose.
Iframes will change the page in the middle. This makes it so you only need to have the layout code on one page, your index page. Just name the page you put the code on index.html. The page you want to show when you first see your layout is what goes into the src="" place. You can make it your homepage and call it home.html. Most sites use cutenews and have their cutenews url in that location.
Linkage In Iframes
Iframe links work a little differently than regular types of links.
Regular Link:
<a href="http://">Link</a>
Iframe Link:
<a href="http://" target="iframe">Link</a>
New-Window Link:
<a href="http://" target="_blank">Link</a>
Which Do I Use?
You only need to use the Iframe link when making link on the outside of the middle for pages that you want to appear in the middle. If you want the link to change the full page, use the the regular link. If you want the page to open up a new window, use the new-window link.
The Good, The Bad & The Ugly
The good thing about iframes is that you do not need to copy and paste your links onto EVERY page every time you want to add a new link or copy and paste your whole layout when you change layouts. You only need to add links to your index.html.
The downside to iframes is that sometimes images won't fit within the iframe. If this happens, I would re-size your image.
If you intend to have a link that is on a page that will be shown within the iframe leave your site, use the new window link.