function show_layer(layer) { 

	/**
	if (document.getElementById(layer).style.visibility == "visible") { 
			// Found it, let's set the style and bail out. 
			document.getElementById(layer).style.visibility = "hidden";	
		
	} else { 
		// Show the layer. 
		window.document.getElementById(layer).style.visibility = "visible";
	}
	**/
	if (document.getElementById(layer).style.display == "block") { 
			// Found it, let's set the style and bail out. 
			document.getElementById(layer).style.display = "none";	
		
	} else { 
		// Show the layer. 
		window.document.getElementById(layer).style.display = "block";
	}
	
	return;
}