title: CSS, auto resize div?
body: <p>I'm trying to design a layout with css, I got one main container(div) and two inner container(div_upper and div_lower). let say I want to resize div_upper and div_lower will automatically resize itself and both divs still fit in the main container. I'm sure this can be done in javascript, but is there any CSS to accomplish this? if so I would be glad.</p>