How do I use CSS to set height of a section using % like frames
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?