var last_layer = "";
var hide_layer = "";
var timerID = 0;
var last_indicator = null;
var indicator_off = "beijing2007/img/pijltje_topnav_0.gif";
var indicator_on = "beijing2007/img/pijltje_topnav_1.gif";

function turnoff_indicator ()
{
	if (last_indicator != null)
	{
		last_indicator.src = indicator_off;
		last_indicator = null;
	}
}

function hidelayer ()
{	
	if (last_layer != "")
		CSSetStyleVis (last_layer, 0);
	last_layer ="";
	turnoff_indicator();
	reset_timer();
}

function hide_layer_slow()
{
	timerID = setTimeout("hidelayer()", 1000);
}

function reset_timer()
{
	if(timerID) {
      clearTimeout(timerID);
      timerID  = 0;
   }
}


function show_layer (basename, nr, on)
{
	var name = basename+nr;
	var obj = document.getElementById(name);
	if (last_layer != "")
		CSSetStyleVis (last_layer, 0);
	if (on)
	{
		CSSetStyleVis (name, on);
		last_layer = name;
	}
	turnoff_indicator();
	if (on)
	{
		var imgname = "indicator"+nr;
		last_indicator = document.images[imgname];
		if (last_indicator)
		{
			last_indicator.src = indicator_on;
		}
	}
	//obj.style.display = (on)? "block": "none" 
}



function show_class (nr, classname)
{
	var name = "menu"+nr;
	var obj = document.getElementById(name);
	obj.className = classname;
	/*
	if (on)
		obj.className = classname; //"menuhover";
	else
		obj.className = "menu";
	*/
}