It's often helpful to have the header, footer and menu always visible on the screen.
Without using iframes, it is possible to make ordinary <div> layers scroll.
There is also a CSS property position:fixed; but IE doesn't recognise it.
I have made a test page that I would like you all to try in your browser, so that we can get an idea of when it works.
http://www.jrd.barrysworld.net/test/fixed_header1.html
It was not a simple task due to the differences in IE6 and MozillaFirebird in which I tested it.
It made it this far by trial and error and a crude knowledge of tricks used in CSS to make things work cross-browser.
It should be centered horizontally.
Here is how it should look (size reduced):
Please report results by replying with you OS and browser version.
[No point in replying if it's already been tested in the same browser/os combination as yours
and they had the same results.]