// JScript 文件
var winWidth = 0;

var winHeight = 0;

function findDimensions() //函数：获取尺寸
{
//获取窗口宽度

if (window.innerWidth)

winWidth = window.innerWidth;

else if ((document.body) && (document.body.clientWidth))

winWidth = document.body.clientWidth;

//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;

winWidth = document.documentElement.clientWidth;

}
}
findDimensions();
//调用函数，获取数值
window.onresize=findDimensions;
function boxleft()
{
findDimensions();
var leftinfo=winWidth-1000;
var leftprot=0;
if(leftinfo>0)
{
leftprot=parseInt(leftinfo/2);
}
$("#box").css("margin","0px "+leftprot+"px 0px "+leftprot+"px");
}
window.onresize = function(){
      boxleft();        
       }