I'm not sure if this is the right place to ask this, so if it is not please direct me where to go.

I want to create a simple webpage that has two sections. The top section must be 80% of the window's height regardless of the size of the window, or if the window is resized. Ordinarily I would use frames, but I understand the prefered technique now is to use CSS. How do I use CSS to do this?

So far I understand a style could be assigned with a height specified (eg. using a <div style="height: [something]"></div>). But percentages don't work for this parameter and I don't know how to get the pixel height of this parameter into the style when the window is sized.

Also with frames I could resize the frame by dragging the seperator between the top and bottom sections. How would I do this with CSS?

have you even tried using %?
i would suggest you have a little look at w3schools.com

I went back and checked (using % as I had before), but did it in Notepad instead of the Netbeans 6 IDE. It turns out that it works with Notepad, but not with Netbeans (I don't have a clue why). Thanks for the help.

As for dragging the border between the top half and the bottom half, any suggestions?

These kind of things are complicated by CSS browser compatibility problems. See www.alistapart.com for some good general info on formatting with CSS.