function prepare()
{
  var index_buttons = document.getElementsByClassName("buttons");
  if (index_buttons && index_buttons.length > 0)
  {
    for (var i=0; i<index_buttons.length; i++)
    {
      var e = index_buttons[i];
      addEvent([{obj:e,evt:"mouseover",fkt:addClass,ctrl:false},
                {obj:e,evt:"mouseout",fkt:removeClass,ctrl:false},
                {obj:e,evt:"click",fkt:doit,ctrl:false}]);
    }
  }
}
function addClass(evt)
{
  var t = evt.target;
  t.classList.add("view");
}
function removeClass(evt)
{
  var t = evt.target;
  t.classList.remove("view");
}
function doit(evt)
{
  var t = evt.target;
  var e = t.parentNode;
  var url = window.location.href;
  var newpart = e.dataset.url;
  if (newpart.indexOf(":") < 0)
  {
    var newurl = url.replace("index",newpart);
    window.location.href = newurl;
  }
  else
  {
    var newurl = newpart.replace("(at)","@");
    window.location.href = newurl;
  }
}
function change_language(lg)
{
  var url = window.location.href;
  var p = url.indexOf("/index.html");
  var pl = p - 2;
  var old = url.substr(pl,2);
  if (old != lg)
  {
    var newurl = url.substr(0,pl) + lg + "/index.html";
    window.location.href = newurl;
  }
  else
  {
    var newurl = url.substr(0,pl) + lg + "/login.html";
    var lgin = window.open(newurl,"login","width=350,height=200");
    lgin.focus();
  }
}