activeMenu = "";
menuTime = "";

function showMenu(menu){
	rollOn();
	
	var divString  = menu+"Sub";
	theDiv = document.getElementById(divString);
	
	if(activeMenu && activeMenu!=theDiv){
		clearMenu();
	}
	
	theDiv.style.display = 'block';
	
	activeMenu = theDiv;
}

function clearMenu(){
	if(activeMenu){
		activeMenu.style.display = 'none';
	}
}

function rollOut(){
	menuTime = setTimeout('clearMenu()', 500);
}

function rollOn(){
	if(menuTime){
		clearTimeout(menuTime);
	}
}