function rb_loadMainframe(){
  var sSearch = top.location.search;
  if (sSearch.length>0){
    if (sSearch.indexOf('sommerbuch')>-1){
      top.frames['rb_Hauptframe'].location.href='sommerbuch/index1.htm';
    } else {
      top.frames['rb_Hauptframe'].location.href=sSearch.substring(5,sSearch.length);
    }
  }
}