How to change a user name

Can I change my user name after I have registered?
No, the username can not be changed. It uniquely identifies you in the network. If you change your username, this will be extremely confusing to others who have you in their contact lists, especially if later someone else registers with your old name. If you wish to change it anyway, you can create another account with the new name that you want and contact your network administrator to close your previous account.