function setFilter(el) {
   var filterItems = document.getElementById('header_filter').getElementsByTagName('a');
   var reqStr = new Array();
   var j=0;
   for (var i=1; i<filterItems.length; i++) {
      if (filterItems[i] == el) {
        if (filterItems[i].className != 'active') {
          reqStr[j++] = filterItems[i].id.substring(7,filterItems[i].id.length);
        } else {
          if (filterItems[i].className == 'active') reqStr[j++] = filterItems[i].id.substring(7,filterItems[i].id.length);
        }
      }
    }
    if (reqStr.length == 0 ) document.location = document.location.pathname + "?filter=reset";
    else document.location = document.location.pathname + "?filter=" + reqStr.join(',');
    return false;
}