title: CSS: 100% height content area with variable-height header
body: <p>I have a page with a variable-height header, content area, and footer.  I want the content area to always fill the viewport, and grow vertically to fit content as necessary.  I've found lots of examples of doing this with fixed-height headers, but none where the height is unknown.</p>
  
  <p>Any solution needs to work in IE 6, 7 and 8, Firefox 3.x and Safari 4.  Can this be done with pure CSS?  Do I have to give in and resort to table-based layout?</p>
  
  <p>EDIT:
  An additional requirement is that I can place elements inside the content area and get them to expand to the full height of the content area (be it viewport height - header height - footer height or larger than that).  Some of the content we want to display has "header" and "footer" sections of their own, so what I'm really looking for is a nestable solution.</p>