Problema popunder

<script type="text/javascript">
var popunder1="link1"
var popunder2="link2"


var winfeatures="width=800,height=510,scrollbars=1,resizable=1,toolbar=1,location=1,menubar=1,status=1,directories=0"


var once_per_session=1


function get_cookie(Name) {
var search = Name + "="
var returnvalue = "";
if (document.cookie.length > 0) {
offset = document.cookie.indexOf(search)
if (offset != -1) { // if cookie exists
offset += search.length
// set index of beginning of value
end = document.cookie.indexOf(";", offset);
// set index of end of cookie value
if (end == -1)
end = document.cookie.length;
returnvalue=unescape(document.cookie.substring(offset, end))
}
}
return returnvalue;
}

function loadornot(){
if (get_cookie('popunder')==''){
loadpopunder()
document.cookie="popunder=yes"
}
}

function loadpopunder(){
win2=window.open(popunder1,"",winfeatures)
win3=window.open(popunder2,"",winfeatures)
win2.blur()
win3.blur()
window.focus()
}

window.onload = function() {
   document.body.onclick = function() {
      if (once_per_session==0)
         loadpopunder();
      else
         loadornot();
   }
}


</script>