Conceal Answerback Message

  When this button is selected, the answerback message entered
  into the "Answerback Message" text entry field will not be
  displayed in the dialog box.

  Once selected, this button cannot be deselected.  The only way
  to deselect it, is to select the "Answerback Message" text entry
  field, which will erase the previous answerback message.