/**
  * Create a default filename given the current date selection. If custom dates are selected, use
  * those dates; otherwise, use year and week numbers.
  *
  * @return The default filename.
  */
 private String getDefaultFilename() {
   if (yearCB.getSelectedIndex() == 0 || weekCB.getSelectedIndex() == 0)
     return "timesheet-"
         + dateFormat.format(fromDate.getDate()).replaceAll("/", "")
         + "-"
         + dateFormat.format(toDate.getDate()).replaceAll("/", "")
         + ".txt";
   return "timesheet-" + yearCB.getSelectedItem() + "wk" + weekCB.getSelectedItem() + ".txt";
 }
 /**
  * Checks whether the interval has been set using the date chooser.
  *
  * @return True if custom.
  */
 boolean isIntervalCustom() {
   return yearCB.getSelectedIndex() == 0 || weekCB.getSelectedIndex() == 0;
 }