Source : Free On-Line Dictionary of Computing

Don't do that then!
     
         (From an old doctor's office joke about a patient
        with a trivial complaint) A stock response to a user
        complaint.  "When I type control-S, the whole system comes to
        a halt for thirty seconds."  "Well don't do that then!"
     
        [{Jargon File}]
     
        (1998-12-13)