function toggleLayer( whichLayer ){  
	var elem, vis;
	if( document.getElementById ) // this is the way the standards work    
		elem = document.getElementById(whichLayer);  
	else 
		if( document.all ) // this is the way old msie versions work      
			elem = document.all[whichLayer];
		else 
			if( document.layers ) // this is the way nn4 works    
				elem = document.layers[whichLayer];  
				vis = elem.style;  // if the style.display value is blank we try to figure it out here  
				if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)    
					vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';  
					vis.display = (vis.display==''||vis.display=='block')?'none':'block';
}

function none(){}

//-->