[NTG-context] local environments

Hi: I have a project with a few different types of documents, so I want to set up a few local environments in the same global environment file. Is the following a legitimate environment file? \startenvironment Layout ... some global settings ... \startlocalenvironment[Alternative] ... some local settings ... \stoplocalenvironment \stopenvironment If it is legitimate, how do I specify that a document use the global settings with specific settings from the local environment. I tried \environment Layout \localenvironment Alternative but any macros defined in the local environment are reported as undefined. Thanks, Matt