var link_last = 'default';
var block_last = 'default_block';

function subMenu(o)
{
	var link_id = document.getElementById(o.id);
	var block_id = document.getElementById(o.id + '_block');
	var last_link_id = document.getElementById(link_last);
	var last_block_id = document.getElementById(block_last);

	if (link_last != o.id)
	{
		link_id.className = 'link_select';
		block_id.className = 'visible';
		if (last_block_id.className = 'visible')
			{			
				last_link_id.className = 'link';
				last_block_id.className = 'invisible';
			}
		link_last = o.id;
		block_last = o.id + '_block';
					
	}
}