the environment environments may be selected by users in a variety of ways for example audio or video user inputs may be processed or used to select or modify an environment also a robot or other program communicating with a user may select or modify an environment other context information about the user 39 s system a specified default environment or set of environments or message content may select or modify an environment one environment may select or modify another environment and a central instant messaging server may itself specify or modify an environment if an instant messaging application passes an environment identifier that is not accepted by the receiving instant messaging application then the receiving instant messaging application will send back the default environment identifier and the sending instant messaging application may either change back to the default environment or maintain its own environment according to how it is configured thus the instant messaging environment is either maintained or changed with each message passed back and forth containing an environment identifier fig4 is a flow chart illustrating a process executed by an instant messaging application when an environment identifier is received the environment identifier is received in step 400 next in step 402 it is determined whether the sender of the identifier is an authorized.