var prev_index = null;
function display_menu(index)
{
	var obj = window.document.getElementById('submenu' + index);
	if(prev_index != null)
	{
		var prev_obj = window.document.getElementById('submenu' + prev_index);
		var top_prev_obj = window.document.getElementById('topmenu' + prev_index);
		top_prev_obj.className = 'topmenu_default';
		prev_obj.className = 'hidelayer';
	}
	if(obj != null)
	{
		var top_obj = window.document.getElementById('topmenu' + index);
		top_obj.className = 'topmenu_over';
		obj.className = 'showlayer submenu_default';
	}
		
	prev_index = index;
}

function hide_menu(index)
{
	var obj = window.document.getElementById('submenu' + index);
	
	if(obj != null)
	{
		var top_obj = window.document.getElementById('topmenu' + index);
		top_obj.className = 'topmenu_default';
		obj.className = 'hidelayer';	
	}
}