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.
A JComboBox is unEditable by default. You can make it editable with the setEditable(boolean) command. If you are talking about enabled or disabled you can set that by the setEnabled(boolean) method. Setting a JComboBox enabled(false) will not allow the drop down to be activated. Editing means you can type in your own text into the text field of the Combo Box.