You are about to execute a command that will cause the
changes you have made to a loaded file since the last the
last time you saved it to be lost. Either:
  ■ Choose <Yes> to save the file, preserving your
    changes, and then finish executing this command.
  ■ Choose <No> to finish executing this command without
    saving the file. Use this choice to throw away work
    that you do not wish to save.
  ■ Choose <Cancel> to stop the command, leaving everything
    just as it was before you chose this command.