控制子窗口的高度

 if (iframe.get(0).attachEvent) {
            iframe.get(0).attachEvent("onload", function () {
                var new_h = iframe.get(0).contentWindow.document.documentElement.offsetHeight + document.getElementsByClassName('nav')[0].offsetHeight;
                iframe.get(0).height = h >= new_h ? (h - 34) : (new_h - 34);;

            });
            return;
        } else {
            iframe.get(0).onload = function () {//将子iframe的高度设置为子页面的高度

                var new_h = iframe.get(0).contentDocument.body.offsetHeight + document.getElementsByClassName('nav')[0].offsetHeight;

                iframe.get(0).height = h >= new_h ? (h) : (new_h);
                //iframe.get(0).height = new_h;
            }
        };