function toggleLayer( layername, mode )
{
	var layer = document.getElementsByName( layername );
	if( layer.length < 1 ) return false;
	
	for( var i = 0; i < layer.length; i++ )
	{
		if( mode == null )
		{
			if( layer[i].style.display == "none" ) layer[i].style.display = "inline";
			else layer[i].style.display = "none";
		} else {
			layer[i].style.display = mode;
		}
	}
}