mred:unsaved-warning

• (mred:unsaved-warning file action now?) -> 'continue, 'cancel, or 'save
      file : pathname string
      action : string
      now? = #f : boolean

  Warns the user that the specified file is not saved. The action argument should be a string that indicates what action is being taken (e.g., ``Quit''). If the user chooses to proceed without saving, the return value is 'continue. If the user chooses to cancel, the return value is 'cancel. If now? is not #f, then the user may also elect to save the file and continue, in which case the return value is 'save.

  This function uses the currently active frame as the default frame.