If I got it correct, here is what I placed in the footer..
Also place the JQuery in the header
But..... The image is not showing up....
<script>$("#upper_section").css("background-image","<img src="http://i1270.photobucket.com/albums/jj612/snuffbottlesplus/vacation2_zps21bbffe2.jpg" border="0" alt="Photobucket"></a>");</script>