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';
	
	if(vis.display=="none") { document.getElementById('show-hide-text').innerHTML='Show'; }
	else { document.getElementById('show-hide-text').innerHTML='Hide'; }
}