Window.onDomReady(function(){

$ES('div.postbody img').each(
    function (el){

        //el.setStyle('display', 'none');
    });

});

Window.addEvent('load', function(){

$ES('div.postbody img').each(
    function (el){

        width = el.width;
        height = el.height;
        maxWidth = 600;

        if (width > maxWidth) 
        {
          scale =1-((width - maxWidth) / width);
          el.width= width * scale;
          el.height= height * scale;
        }

    });

});