If you want to save your models into a private directory, you
have to be a registered user. Registering is free and you do not
have any obligations.
To register as a new user, choose Save... in File-menu. Press
Register as a New User and a new window should appear.
There is a registeration form in the new window. Fill all required
fields and submit registeration. Please, write down any username
and the related password you have created. The system does not
allow you to ahow a list of usernames.
After the registeration just enter your own Username and password
to save your models in a private directory.
You can open your own saved models by choosing Open... in File-menu
and entering your own username and password.