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";
	  }
	}