"Now when we can send messages and everything looks okay we are almost done with the user interface part. But later we will have a chatbot also writing messages and have to recognize which message comes from the chatbot and which from the user. This is why we need a username. In this tutorial it will only be "You", but in one of next tutorial we will teach the chatbot to ask for our name and the it will be shown before every message."
http://www.mybringback.com/?p=13748