js基础 DIV高度自动调节

js获取浏览器可见区域(不包括标题栏、地址栏、收藏夹栏状态栏等额外区域，仅为页面呈现区域)的高度和宽度宽度：document.documentElement.clientWidth 高度：document.documentElement.clientHeight 文档类型：XHTML1.0 浏览器：ALL 然后就是获取区块的高度

function AdjustColumnsHeight() {

var mainCol = window.document.getElementById('MainColumn');

var leftCol = window.document.getElementById('MainLeft');

var rightCol = window.document.getElementById('MainRight');

var hMainCol = mainCol .offsetHeight;

var hLeftCol = leftCol.offsetHeight;

var hRightCol = rightCol.offsetHeight;

var maxHeight = Math.max( hMainCol , Math.max(hLeftCol, hRightCol));

mainCol.style.height = maxHeight + 'px';

leftCol.style.height = maxHeight + 'px';

rightCol.style.height = maxHeight + 'px';

}

然后就是加以计算 下面是我写的仅供参考 一秒换挡。。 很基础的东西 扎实一点吧

function heighta(){

var a =document.documentElement.clientHeight;

var ac21 =window.document.getElementById("ac21");
var ac22 =window.document.getElementById("ac22");
var ac23 =window.document.getElementById("ac23");
var ac24 =window.document.getElementById("ac24");

var top =window.document.getElementById("top_nav");
var ht =  top.offsetHeight;
var bottom_nav =window.document.getElementById("bottom_nav");
var hb =  bottom_nav.offsetHeight;

var res=parseInt(a-ht-hb)/2;

ac21.style.height=res+"px";
ac22.style.height=res+"px";
ac23.style.height=res+"px";
ac24.style.height=res+"px";

window.setTimeout("heighta()",1000);
}

window.onload=heighta;