function startpopup()
{
    document.getElementById('popup').style.display = "none";
}

function popup(menuId)
{
	if(document.getElementById(menuId).style.display == "none")
	{
		startpopup();
		document.getElementById(menuId).style.display = "block";
	}
	else
	{
		startpopup();
	}
}