The environment statement specifies the name of environment to use for resolving global variables.
The environment statement selects the predefined environment to use for global variable lookup. It is and error to specify the environment which is not defined in global database.
If no environment specified, default environment (the one specified as default in global database) is assumed.
Environment can be changed many times without limitations, and change affects only global variables that are referenced first time within the script, e.g. all global variables, resolved (copied to local variables) retain their values.