Event.observe(window, 'load', function(){
    $$('#image-thumbs img').each(function(e, i){
        Event.observe(e, 'mouseover', function(){
            $$('#image-preview img').each(function(img, i){
            	img.src = 'files/item_files/thumbs/'+e.id+'.w-181_h-145_zc-1.jpg';
            });
        });
    });
});