var pagina = document.location.pathname;
var adres = document.location.href
var idnummer = adres.indexOf('?');
var loctest = adres.substring(0, 4);

if (parent.location.href == self.location.href && loctest == 'http') {
if (idnummer > -1){
idnummer = adres.substring(idnummer, 130);
pagina = pagina + idnummer
}
document.write('<form name="pagina" method="post" action="http://www.rijnsburgseboys.nl">');
document.write('<input type="hidden" name="main" value="' + pagina + '">');
document.pagina.submit();
}