var timer;

function showSubMenu(submenu_name){
	
	var el;
	
	if(el = document.getElementById(submenu_name)){
	
		el.style.display = "";
		
	}
	
}

function clearSubMenuTimer(){

		clearTimeout(timer);
	
}

function startSubMenuTimer(submenu_name){

		clearTimeout(timer);
		timer = setTimeout ( "closeSubMenu('"+submenu_name+"')", 500 );

}

function closeSubMenu(submenu_name){
	
	var el;
	
	if(el = document.getElementById(submenu_name)){
	
		el.style.display = "none";
		clearTimeout(timer);
		
	}
	
}