用jquery等比例控制图片宽高

$(function() {
    $(".dvcontent img").each(function() {
        var maxwidth = 520;
        if ($(this).width() > maxwidth) {
            var oldwidth = $(this).width();
            var oldheight = $(this).height();
            var newheight = maxwidth/oldwidth*oldheight;
            $(this).css({width:maxwidth+"px",height:newheight+"px",cursor:"pointer"});
            $(this).attr("title","点击查看原图");
            $(this).click(function(){window.open($(this).attr("src"))});
        }
    });
});