TreePanel随浏览器的高度改变高度

Ext.onReady(function () {

               var winHeight = 0;
                //获取窗口高度
                if (window.innerHeight)
                    winHeight = window.innerHeight;
                else if ((document.body) && (document.body.clientHeight))
                    winHeight = document.body.clientHeight;
                //通过深入Document内部对body进行检测，获取窗口大小
                if (document.documentElement && document.documentElement.clientHeight && document.documentElement.clientWidth) {
                    winHeight = document.documentElement.clientHeight;
                }
                Ext.getCmp("TreePanel").setHeight(winHeight-125);

}