function submenuHover(id){
	$('submenu_item_' + id + '_a').style.visibility = 'visible';
	$('submenu_item_' + id + '_b').style.visibility = 'visible';
	$('submenu_' + id).style.fontWeight = 'bold';
}

function submenuHidden(id){
	$('submenu_item_' + id + '_a').style.visibility = 'hidden';
	$('submenu_item_' + id + '_b').style.visibility = 'hidden';
	$('submenu_' + id).style.fontWeight = '';	
}