Demo : https://suctreviet.123.st/html-h16.htm

<div id="divAdLeft" style="left: -110px; position: absolute; top: 71px; width: 0px;" align="right">
<a href="http://www.code1k.com/" target="blank"><img border="0" width="100" src="http://c.upanh.com/upload/7/290/CS0.11501477_1_1.gif" height="480alt="/></a></div>

<div id="divAdRight" style="left: -110px; position: absolute; top: 71px; width: 0px;">
<a href="http://www.code1k.com" target="blank"><img border="0" width="100" src="http://c.upanh.com/upload/7/290/CS0.11501835_29781_1.gif" height="480alt="/></a></div>

<script language="JavaScript">
function FloatTopDiv()
{
startX = document.body.clientWidth - 110, startY = 71;
var ns = (navigator.appName.indexOf("Netscape") != -1);
var d = document;

if (document.body.clientWidth < 980) startX = -110;
function ml(id)
{
var el=d.getElementById?d.getElementById(id):d.all?d.all[id]:d.layers[id];
if(d.layers)el.style=el;
el.sP=function(x,y){this.style.left=x;this.style.top=y;};
el.x = startX;
el.y = startY;
return el;
}

window.stayTopLeft=function()
{

if (document.body.clientWidth < 980)
{
ftlObj.x = - 115;ftlObj.y = 0; ftlObj.sP(ftlObj.x, ftlObj.y);
}

else
{
if (document.documentElement && document.documentElement.scrollTop)
var pY = ns ? pageYOffset : document.documentElement.scrollTop;
else if (document.body)
var pY = ns ? pageYOffset : document.body.scrollTop; if (document.body.scrollTop > 71){startY = 3} else {startY = 71}; if (document.body.clientWidth >= 1024)
{
ftlObj.x = document.body.clientWidth - 110;ftlObj.y += (pY + startY - ftlObj.y)/32;ftlObj.sP(ftlObj.x, ftlObj.y);
}
else
{

ftlObj.x = startX;
ftlObj.y += (pY + startY - ftlObj.y)/32;
ftlObj.sP(ftlObj.x, ftlObj.y);
}
}
setTimeout("stayTopLeft()", 1);
}

ftlObj = ml("divAdRight");
stayTopLeft();

}
function FloatTopDiv2()
{
startX2 = document.body.clientWidth - 1004, startY2 = 71;
var ns2 = (navigator.appName.indexOf("Netscape") != -1);
var d2 = document;

if (document.body.clientWidth < 980) startX2 = -110;
function ml2(id)
{
var el2=d2.getElementById?d2.getElementById(id):d2.all?d2.all[id]:d2.layers[id];
if(d2.layers)el2.style=el2;
el2.sP=function(x,y){this.style.left=x;this.style.top=y;};
el2.x = startX2;
el2.y = startY2;
return el2;
}

window.stayTopLeft2=function()
{
if (document.body.clientWidth < 980)
{
ftlObj2.x = - 115;ftlObj2.y = 0; ftlObj2.sP(ftlObj2.x, ftlObj2.y);
}
else
{
if (document.documentElement && document.documentElement.scrollTop)
var pY2 = ns2 ? pageYOffset : document.documentElement.scrollTop;
else if (document.body)
var pY2 = ns2 ? pageYOffset : document.body.scrollTop; if (document.body.scrollTop > 71){startY2 = 3} else {startY2 = 71}; if (document.body.clientWidth >= 1024)
{
ftlObj2.x = 0;ftlObj2.y += (pY2 + startY2 - ftlObj2.y)/32; ftlObj2.sP(ftlObj2.x, ftlObj2.y);
}
else
{

ftlObj2.x = startX2;
ftlObj2.y += (pY2 + startY2 - ftlObj2.y)/32;
ftlObj2.sP(ftlObj2.x, ftlObj2.y);
}
}
setTimeout("stayTopLeft2()", 1);
}

ftlObj2 = ml2("divAdLeft");
stayTopLeft2();

}
function ShowAdDiv()
{
var objAdDivLeft = document.getElementById("divAdLeft");
var objAdDivRight = document.getElementById("divAdRight");
if (document.body.clientWidth < 980)
{
objAdDivLeft.style.left = - 110;
objAdDivRight.style.left = - 110;
}

else
{
objAdDivLeft.style.left = 0;
objAdDivRight.style.left = document.body.clientWidth - 110;
}
FloatTopDiv();
FloatTopDiv2();
}
ShowAdDiv();
</script>

Bạn admin có thể sao chép code từ Code1k.com nhưng ko nên sửa nguồn thành của chính bạn như vậy. xấu lắm