This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
It's difficult to troubleshoot this without seeing the stack trace of the error. I'm also suspicious because if the setContentView() method was the problem, you wouldn't have a button to click because the app would have already crashed before you got that far (I'm referring to your post at stackoverflow.com). One thing I see that is not good is how you check which button is clicked. The usual thing that developers do is something like this: