function nav( divNum,divTot )
{
	var id = 0;
	var display = "";
	var i = divTot;
	
	// erstmal alles unsichtbar
	while (i > 0)
	{
		document.getElementById('s' + i).style.display = "none";
		i--;
	}

	// dann die geforderte Subnavi anzeigen
	document.getElementById('s' + divNum).style.display = "block";
}