var lastScrollY=0; 
function heartBeatx(){
var diffY; 
if (document.documentElement && document.documentElement.scrollTop) 
    diffY = document.documentElement.scrollTop; 
else if (document.body) 
    diffY = document.body.scrollTop 
else 
    {/*Netscape stuff*/} 
     
percent=.1*(diffY-lastScrollY);  
if(percent>0)percent=Math.ceil(percent);  
else percent=Math.floor(percent);  
document.getElementById("adleftx").style.top=parseInt(document.getElementById("adleftx").style.top)+percent+"px"; 
document.getElementById("adrightx").style.top=parseInt(document.getElementById("adrightx").style.top)+percent+"px"; 
lastScrollY=lastScrollY+percent;  
} 

function adhide(names){document.getElementById(names).style.display='none';}
function screencl(names){if(screen.width<=980){adhide(names);}}
zcode="<div id='adleftx' style='left:0px;position: absolute;z-index:1;top:110px;'><div style='width:135px;height:160px;background:#fff;'><a href='http://www.gct-online.com/guide/2010gct.html' target='_blank'><img src='http://www.gct-online.com/wp-content/uploads/images/ad_l2010.gif' border = 0></a></div><div align='right' style='background:#fff;font-size:0px;'></div></div>";
ycode="<div id='adrightx' style='right:0px;position: absolute;z-index:1;top:110px;'><div style='width:135px;height:160px;background:#fff;'><a href='http://www.gct-online.com/course/preview.html' target='_blank'><img src='http://www.gct-online.com/wp-content/uploads/images/shikan_119.gif' border = 0></a></div><div align='right' style='background:#fff;font-size:0px;'></div></div>";

document.write(zcode);
document.write(ycode);
screencl('adleftx');
screencl('adrightx');
window.setInterval("heartBeatx()",1);