document.observe('dom:loaded', function(){
    var theGalleries = $$('.gallery');
    theGalleries.each(function(elt){
        elt.onmouseover = function() {
            elt.writeAttribute({
                style: 'background:#f2f2f2;cursor:pointer'
            });
        }
        elt.onmouseout = function() {
            elt.writeAttribute({
                style: 'background:none;cursor:default'
            });
        }
    });
    var theThumbs = $$('.thumb');
    theThumbs.each(function(elt){
        elt.onmouseover = function() {
            elt.writeAttribute({
                style: 'background:black'
            });
        }
        elt.onmouseout = function() {
            elt.writeAttribute({
                style: 'background:gray'
            });
        }
    });
});