This environment allows the user to send messages and problem 
                      solutions while performing activities with ARI-LAB 
                      2.
                      In order to use it, the laboratory computers must be connected 
                      through a local network. To enter this environment, the 
                      user has to select the icon “Phone”, available 
                      in the Solution Sheet. 
                    The interface of the communication environment is divided 
                      into three zones.
                      The high left zone contains the names of the users currently 
                      working with ARI-LAB 2. If the user selects 
                      one of these names, the system sends the selected interlocutor 
                      a message requiring a confirmation for starting the communication.
                      In high right zone of the interface, the names of the interlocutors 
                      already communicating with the user are shown.
                      In the bottom zone of the interface the user can write the 
                      text of a message, send it to selected interlocutors, and 
                      see the whole list of messages sent during the communication 
                      with his/her interlocutors. 
                      The user can also send the solution to the current problem 
                      (the problem that is in the Solution Sheet when the user 
                      enter the communication environment) to one of his/her interlocutors.