function changeOrderBy(){
  var orderby = document.getElementById('order_by').options[document.getElementById('order_by').selectedIndex].value;
  var loc =  location.host + location.pathname;
//  alert(loc);
  if(location.search=='')
    loc+='?';
  else
    loc+=location.search+'&';
  
  location.href = 'http://' + loc + 'orderby='+orderby;
}