var _menu=document.getElementById("menu");
var _cnt=document.getElementById("content");
var _sizer=document.getElementById("sizer");
var _min=_menu.clientHeight;
window.onresize=function(){setH()}
setH();
function setH(){
h=_sizer.clientHeight-310;
if(h<_min && _menu.clientHeight<_min) return;
h=(h<=_min ? _min : h);
_menu.style.height=Number(h-60)+"px";
_cnt.style.height=h+"px";
}