Sandbox framework and footer problem.

Hy there, I’m trying Sandbox wordpress framework in local, and I have the problem that the footer that is positioned just below the sidebar:

http://img2.pict.com/fa/cd/87/3462884/0/800/footer.png

How do I place it always at the bottom regardless of the number of posts you have on your blog?

This is the main css code:

div#container { float:right; margin:0 0 0 -200px; width:100%; }
div#content { margin:0 0 0 200px; }
div.sidebar { float:left; overflow:hidden; width:180px; border-right: 2px solid #ccc; }
div#secondary { clear:left; }
div#footer { clear:both; width:100%; }

Thanks if you can help me!