lastPos = 0;
function winAd(){
	var barPos;
	if(document.documentElement&&document.documentElement.scrollTop){
		barPos = document.documentElement.scrollTop;	
	}else if(document.body){
		barPos = document.body.scrollTop;
	}	
	var percent = 0.1*(barPos-lastPos);//滚动条行进距离
	if(percent>0){
		percent=Math.ceil(percent);
	}else{
		percent=Math.floor(percent);	
	}
	document.getElementById("rightDiv").style.top = parseInt(document.getElementById("rightDiv").style.top)+percent+"px";
	lastPos += percent;//向0靠近
	//window.document.title = "滚动条位置："+barPos
}
setInterval(winAd,1);