Making a footer not rise above the bottom of the screen without extraneous markup

Question

If you only had to worry about Firefox and Webkit browsers, what CSS would you use to make the footer in the following HTML not rise above the bottom or the screen (and go lower

Answer 1

Working and tested on:
Google Chrome
Safari
Opera
Internet Explorer
Firefox

EDITED CODE (added overflow:auto; to #aside and #Article to fix the overflow)

    
      
        
      
      
        
Header
        
Article
        
Aside
        
Footer
      
    

PS: Background colors are illustrative, thus the css can me more compact by avoiding repeated attributes!