var scrollTop=docHeight=divHeight=divLeft=divWidth=docWidth=0;
docHeight = document.documentElement.clientHeight;
divHeight = 534;//div的高度
divWidth = 480;//div的宽度
scrollTop = parseInt(document.documentElement.scrollTop);
docWidth = document.documentElement.clientWidth;

function setdivlocal(){
	try{
		var page_height = document.body.scrollHeight;//获取网页全文高度
		document.getElementById('mbox_overlay').style.height = page_height+"px";
		docHeight = document.documentElement.clientHeight;
		scrollTop = parseInt(document.documentElement.scrollTop,10);
		docWidth = document.documentElement.clientWidth;
		document.getElementById("mbox-window").style.top = parseInt((docHeight-divHeight+scrollTop))+"px";
		document.getElementById("mbox-window").style.left = parseInt((docWidth-divWidth)/2)+"px";
		window.setInterval("moveDiv()",1);
	}catch(e){}
}
function moveDiv(){
	try{
		//var page_height = document.body.scrollHeight;
		//document.getElementById('mbox_overlay').style.height = page_height+"px";
		docHeight = document.documentElement.clientHeight;
		scrollTop = parseInt(document.documentElement.scrollTop,10);
		docWidth = document.documentElement.clientWidth;
		document.getElementById("mbox-window").style.top = parseInt((docHeight-divHeight+scrollTop))+"px";
		document.getElementById("mbox-window").style.left = parseInt((docWidth-divWidth)/2)+"px";
	}
	catch(e){}
}