How to implement a web page that scales when the browser window is resized?

Question

How to implement a web page that scales when the browser window is resized?

I can lay out the elements of the page using either a table or CSS float sections, but i

Answer 1

Use percentages! Say you have a "main pane" on which all your page's content lies. You want it to be centered in the window, always, and 80% of the width of the window.

Simply do this:
#centerpane{ margin: auto; width: 80%; }

Tada!