how to cut off the bottom of a page with css or html?

Link? It's hard to tell just based on a description.

Make that containing DIV's overflow:hidden and then give it a fixed height

Also, I would make that background always centered like the middle white box is and set it all on a blue background color instead of the white.

Wrap all content in a single div with an ID. Set its height and width to whatever you want in pixels in the associated CSS also add in the following:

overflow: hidden;

Notes:

A full explanation of overflow is found here.

As to positioning elements, anything outside the "flow" will display no matter what you do. If you position objects in this manner, then apply the height/width and overflow to the body tag in your CSS but -- I've never tried that so test it carefully. If all else fails, resort to creating an iframe and set the scrolling=no, but it's your last resort, a horrible way to do it. The best fix is NOT to position any elements outside the flow, keeps things very simple and the method I listed first works great.

-jim

Haven't seen exactly what you mean, but remember that web pages are displayed in a lot of different browsers, on a lot of different operating systems, and (especially) a LOT of different screen resolutions.

If I understand your problem accurately, I've had the same problem before (well, once before). I forget how I resolved now, but I seem to remember it was something related to float and width of certain elements.