This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
Well, because there is no code in the commandAction method to handle the user selecting the command
public static final int BACK
A navigation command that returns the user to the logically previous screen. The jump to the previous screen is not done automatically by the implementation but by the commandAction provided by the application. Note that the application defines the actual action since the strictly previous screen may not be logically correct. Value 2 is assigned to BACK.