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.
Your problem is with the percent symbol, "%", as the printf method thinks that it's a format specifier. To use it literally as a percent symbol, you'll need to use two of them in a row. So change this: