// show / hide menu
var currentMenu = null;
function ShowMenu(menu)
{
	if (currentMenu != null)
		currentMenu.className = "hiddenMenu";
		
	currentMenu = menu;
	currentMenu.className = "visibleMenu";
}
		
function HideMenu()
{
	if (currentMenu != null)
		currentMenu.className = "hiddenMenu";
	currentMenu = null;
}