// The following functions work for only IE5+ and NN6+

function hideAllMenus()
{
	var i=1;
	
	var subMenu;
	
	while(subMenu=document.getElementById('subMenu'+i))
	{
		subMenu.style.visibility='hidden';
		i++;
	}
	
	return true;
}

// showSubMenu() accepts the ID of a submenu and makes it visible

function showSubMenu(subMenu)
{
	// W3C DOM 1
	
	hideAllMenus();

	var sM=document.getElementById(subMenu);
	
	sM.style.visibility="visible";
	sM.style.zIndex="1";

	return true;
}

// hideSubMen() accepts the ID of a submenu and makes it invisible

function hideSubMenu(subMenu)
{
	
	// W3C DOM 1
	
	var sM=document.getElementById(subMenu);
	
	sM.style.visibility="hidden";
	
	return true;
}

document.onmouseover=hideAllMenus;