function bg_img_resize() 
{
     var w = $(window).width();
     var h = $(window).height();
     var iw = $('#the-background img').attr('width');
     var ih = $('#the-background img').attr('height');
     var rw = iw / ih;
     var rh = ih / iw;
     var sc = h * rw;
     if (sc >= w) {
         nh = h;
         nw = sc;
     } else {
         sc = w * rh;
         nh = sc;
         nw = w;
     }
     $('#the-background img').css({height: nh, width: nw});
 }
$(document).ready(function(){ bg_img_resize(); });
$(window).resize(function(){ bg_img_resize(); });