var showadsign=1;
var BROWSERNAME="";
switch(navigator.appName.toLowerCase()){
 case "netscape":
  BROWSERNAME="ns";
 break;
 case "microsoft internet explorer":
 default:
  BROWSERNAME="ie";
 break;
}

switch(BROWSERNAME){
 case "ns":
  window.addEventListener("load",ad,false);
  window.addEventListener("scroll",ad,false);
 break;
 case "ie":
 default:
  window.attachEvent("onload",ad);
  window.attachEvent("onscroll",ad);
}
document.body.parentNode.onscroll=ad;

function adinit(imgwidth){
if ((document.body.clientWidth-imgwidth*2-40)<1000){
$('left').style.display='none';
$('right').style.display='none';
showadsign=0;
}
else{
$('left').style.display='block';
$('right').style.display='block';
showadsign=1;
}
}

function adshowie(imgwidth,imgheight,imgtopheight){
adinit(imgwidth);
if (showadsign==1){
$('left').style.left=0;
$('right').style.right=0;
$('left').style.top=(document.body.scrollTop+imgtopheight)+'px';
$('right').style.top=(document.body.scrollTop+imgtopheight)+'px';
}
}

function adshow(imgwidth,imgheight,imgtopheight){
adinit(imgwidth);
if (showadsign==1){
$('left').style.left=30+'px';
$('right').style.right=30+'px';
$('left').style.top=(parseFloat(document.documentElement.scrollTop)+imgtopheight)+'px';
$('right').style.top=(parseFloat(document.documentElement.scrollTop)+imgtopheight)+'px';

}
}
function ad(){adshow(107,538,142);}