<!-- beginlayer_ref = ""style_ref = ""old_layer = ""if (navigator.appName == "Netscape"){	layer_ref = ".layers"	style_ref = ""}else{	layer_ref = ".all"	style_ref = ".style"}function show_nav(layer_name){	if (old_layer)	{		hide_layer(old_layer)	}	show_layer(layer_name)	old_layer = layer_name}function hide_nav(){	if (old_layer)	{		hide_layer(old_layer)	}	old_layer = ""}function show_layer(layer_name){	eval( "document" + layer_ref + "[layer_name]" + style_ref + ".visibility = 'visible'" )}function hide_layer(layer_name){	eval( "document" + layer_ref + "[layer_name]" + style_ref + ".visibility = 'hidden'" )}// end -->