function toggleLayer(whichLayer)
{
	if (document.getElementById)
	{
	// this is the way the standards work
	var style2 = document.getElementById(whichLayer).style;
	style2.display = style2.display? "":"block";
	}
else if (document.all)
	{
	// this is the way old msie versions work
	var style2 = document.all[whichLayer].style;
	style2.display = style2.display? "":"block";
	}
else if (document.layers)
	{
	// this is the way nn4 works
	var style2 = document.layers[whichLayer].style;
	style2.display = style2.display? "":"block";
	}
}