function show_error_msg(req) {
   alert("Kommunikációs hiba!\nA szerver nem elérhető!");
}

function update_content(url) {
   if (!url)
      url = "";
   new Ajax.Request(url, {
      onLoading: function(req) {
         $("ajax_indicator").show();
      },
      
      onComplete: function(req) {
         $("ajax_indicator").hide();
         
         if(req.status == 0)
            show_error_msg(req);
      },

      onFailure: function(req) {
         show_error_msg(req);
      },
      
      onException: function(req) {
         show_error_msg(req);
      },
      
      onSuccess: function (req) {
         $("content").innerHTML = req.responseText;
      }
   });
}

function load_content(id, url) {
   dhtmlHistory.add(id, url);
   update_content(url);
}

var onHistoryChange = function(id, url) {
   update_content(url);
}

Event.observe(window, 'load', function() {
	dhtmlHistory.initialize();
	dhtmlHistory.addListener(onHistoryChange);
});

window.dhtmlHistory.create({
	toJSON: function(o) {
		return Object.toJSON(o);
	},
	
   fromJSON: function(s) {
		return s.evalJSON();
	}
});