var layer = '';
var on = ''
var timer;

function activate(number){
	clearTimeout(timer);
	layer = number;
	//check(number);
	timer = setTimeout("check('" + number + "')", 500);	
}

function check(number){
	if(layer == number){
		show(number);
	}
}

function show(number){
	if (on != '')
		hide(on);
	document.getElementById(number).style.visibility = "visible";
	on = number;
}

function hide(number){
	if((number != null) && (number.length > 0))
	document.getElementById(number).style.visibility = "hidden";	
}

function release(){
	clearTimeout(timer);
	timer = setTimeout("hide('" + on + "')", 5000);	
}