l=0
function ss(){
	var d
	if(document.documentElement && document.documentElement.scrollTop)
	d=document.documentElement.scrollTop;
	else if(document.body){

		d=document.body.scrollTop;
	}
	c=0.1*(d-l);
	if(c>0){

		c=Math.ceil(c);
	}
	else{

		c=Math.floor(c);
	}
	document.getElementById("left").style.top=parseInt(document.getElementById("left").style.top)+c+"px";
	document.getElementById("right").style.top=parseInt(document.getElementById("right").style.top)+c+"px";
	l=l+c
}
zuo="<div id=\"left\" style=\" position:absolute; left:20px; top:50px; width:100px; height:300px; text-align:center; \" ><img src=\"images/left.jpg\"><a href=JavaScript: onclick=\"left.style.display='none'\"><img src=\"images/close.gif\"></a></div>"
you="<div id=\"right\" style=\" position:absolute; right:20px; top:50px; width:100px; height:300px; text-align:center; \" ><img src=\"images/right.jpg\"><a href=JavaScript: onclick=\"right.style.display='none'\"><img src=\"images/close.gif\"\"></a></div>"
document.write(zuo)
document.write(you)

window.setInterval("ss()",1);