function keywordGroupChanged() {
    var oOption;
    var groups = document.getElementById('keyword_groups');
    var keywords = document.getElementById('keywords');

    for (var i = keywords.options.length; i > 0; i--) {
      keywords.options[i - 1] = null;
    }

    if (groups.selectedIndex > 0) {
      oOption = new Option('- Válasszon! -', '');
      keywords.options.add(oOption);

      var list = keyword_list[groups.options[groups.selectedIndex].value];

      for (var i = 0; i < list.length; i++) {
        oOption = new Option(list[i].label, list[i].id);
        keywords.options.add(oOption);
      }
    }

    keywords.disabled = keywords.options.length <= 1;
  }

  function keywordChanged() {
    document.getElementById('keywords_submit').disabled = document.getElementById('keywords').selectedIndex <= 0;
  }

  function popup(aURL, aWidth, aHeight) {
    aWidth = (aWidth == undefined || aWidth == null) ? 400 : aWidth;
    aHeight = (aHeight == undefined || aHeight == null) ? 250 : aHeight;

    window.open(aURL, '_blank', 'scrollbar=0, resizable=0, width=' + aWidth + ', height=' + aHeight);
  }

  /********/
  /* Menu */
  /*******/

  var menuDiv = '';
  var subMenuDiv = '';

  function setDivDisplay(aDivName, aDisplay) {
    var d = document.getElementById(aDivName);
    if (d != undefined && d != null)
      d.style.display = aDisplay ? 'block' : 'none';
  }

  function getDivDisplay(aDivName) {
    var d = document.getElementById(aDivName);
    if (d != undefined && d != null)
      return d.style.display != 'none'
    else
      return null;
  }

  function toggleDivDisplay(aDivName) {
    var d = document.getElementById(aDivName);
    if (d != undefined && d != null)
      d.style.display = (d.style.display == 'none' ? 'block' : 'none');
  }

  function toggleDetails(what,who){
    var mit = document.getElementById(what);
    var mivel = document.getElementById(who);
    if (mit != undefined && mit != null){
      mit.style.display = (mit.style.display == 'none' ? 'block' : 'none');
      if (mivel != undefined && mivel != null){
        mivel.src = (mit.style.display == 'none' ? 'images/lenyil.gif' : 'images/felnyil.gif');
        mivel.title = (mit.style.display == 'none' ? 'részletek megjelenítése' : 'részletek eltüntetése');
      }
    }
  }
  function clickMenu(aID) {
    var d = 'menu' + aID;
    if (menuDiv != d)
      setDivDisplay(menuDiv, false);
    setDivDisplay(subMenuDiv, false);
    toggleDivDisplay(d)
    menuDiv = d;
    subMenuDiv = '';
  }

  function clickSubMenu(aID) {
    var d = 'menu' + aID;
    if (subMenuDiv != d)
      setDivDisplay(subMenuDiv, false);
    toggleDivDisplay(d)
    subMenuDiv = d;
  }



  /* Forms */

  function userTypeChanged(aType) {
    var expert = aType == 2;
    var club = aType == 3;

    setDivDisplay('institute', expert);
    setDivDisplay('institute_address', expert);
    setDivDisplay('institute_email', expert);
    setDivDisplay('institute_phone', expert);

    setDivDisplay('club', club);
    setDivDisplay('club_leader', club);
    setDivDisplay('club_email', club);
    setDivDisplay('club_phone', club);
  }