var bgPreloaders = new Array();


function getBackgroundUrl( img )
{
   var url = img.getAttribute("src");
   return url.replace('m.','.');
}


function preloadBackground( )
{
   var bigurl = getBackgroundUrl(this);
   var img = new Image();
   img.src = bigurl;
   bgPreloaders.push(img);
}

function changeBackground( )
{
   var bigurl = getBackgroundUrl(this);
   $("#expando")[0].src = bigurl;
}

var images = $(".photo > img");
images.mouseover(changeBackground);
images.each(preloadBackground);