function ToggleLayer (a_sWhichLayer)
{
	if (document.getElementById)
	{
		var style2 = document.getElementById(a_sWhichLayer).style; 
		style2.display = style2.display? "":"block";
	}
	
	else if (document.all)
	{
		var style2 = document.all[a_sWhichLayer].style;
		style2.display = style2.display? "":"block";
	}
	
	else if (document.layers)
	{
		var style2 = document.layers[a_sWhichLayer].style;
		style2.display = style2.display? "":"block";
	}
}


function ShowLayer (a_sWhichLayer)
{
	var style2;
	var styleOld;
	var sLayer = a_sWhichLayer;
	var sOld = GetLast(sLayer);
	if (sOld == a_sWhichLayer)
		sOld = 'undefined';
	
	if (document.getElementById)
	{
		style2 = document.getElementById(a_sWhichLayer).style;
		
		// alte Anzeige ausblenden
		if ('undefined' != sOld)
		{
			styleOld = document.getElementById(sOld).style;
		}
	}
	
	else if (document.all)
	{
		style2 = document.all[a_sWhichLayer].style;
		
		// alte Anzeige ausblenden
		if ('undefined' != sOld)
		{
			styleOld = document.all[sOld].style;
		}
	}
	
	else if (document.layers)
	{
		style2 = document.layers[a_sWhichLayer].style;
		
		// alte Anzeige ausblenden
		if ('undefined' != sOld)
		{
			styleOld = document.layers(sOld).style;
		}
	}
	
	style2.display = style2.display? "":"block";
	//alert ('activate: ' + a_sWhichLayer);
	if ('undefined' != sOld)
	{
		styleOld.display = "";
		//alert ('deactivate old: ' + sOld);
	}
}


function GetLast (a_sNewValue)
{
	var sReturn = 'undefined';
	
	// überprüfen, ob ein alter Wert eingetragen ist
	if ('undefined' != typeof this.newValue)
	{
		// Wert auslesen
		sReturn = this.newValue;
	}
	
	this.newValue = a_sNewValue;
	//alert (sReturn + ' / ' + a_sNewValue);
	
	return sReturn;
}