var divscroll_div = document.getElementById('scroll_div');
var divcontent = document.getElementById('content');
var Lengte = divscroll_div.offsetHeight;
var FormaatContent = divcontent.offsetHeight;

function checklayer(){

if (document.layers) {
var page = eval(document.content);
}
else {
if (document.getElementById) {
var page= eval("document.getElementById('content').style");
}
else {
if (document.all) {
var page = eval(document.all.content.style);
      }
   }
}

var NwLengte = divscroll_div.offsetHeight;

if(NwLengte != Lengte){

page.top=0;

}
if(FormaatContent < Lengte){
MM_showHideLayers('scrollbar','','show');
}
else{

MM_showHideLayers('scrollbar','','hide');
}

}

checklayer();