var popAdWidth;
var popAdHeight;
var popAd;

// 初始化浮动图层
function popAdLoad(obj)
{
	if (!obj)
	{
		return;
	}		
	
	popAd = obj;
	popAdWidth = parseInt(popAd.style.width);
	popAdHeight = parseInt(popAd.style.height);	
	
	if (explorerInst.isIE) {
		popAdHeight += 4;
	}	
	
	doMove();
	window.onscroll = doMove;
}
// 移动浮动图层
function doMove()
{
	var totalWidth;
	var totalHeight;
	
	if (explorerInst.isIE) {
		totalWidth = document.body.offsetWidth;
		totalHeight = document.body.offsetHeight;
	} 
	else {
		totalWidth = window.innerWidth;
		totalHeight = window.innerHeight;
	}
	
	popAd.style.top = document.body.scrollTop + totalHeight - popAdHeight;
}