function toggleButtonBarItem( whichItem)
{
	var i = 0;
	
	for ( i = 0; i < 7; i++)
	{
		var anItem = document.getElementById('buttonBarBlock_' + i);
	
		if ( anItem != null)
		{
			if ( i == whichItem)
			{
				if ( anItem.style.visibility == 'visible')
				{
					anItem.style.visibility = 'hidden';
				} else
				{
					anItem.style.visibility = 'visible';
				}
			} else
				anItem.style.visibility = 'hidden';
		}
	}

}