(setq dsf/dynamic-screen (lambda nil
  (block nil
    (dsf/screen 'dynamic "Screen One")
    (dsf/action 'switch "Switch" 'S
      (lambda nil (block nil
        (if (eq (dsf/screen-name) "Screen One")
          (dsf/screen-name "Screen Two")
          (dsf/screen-name "Screen One")
        )
        (dsf/show-screen)
      ))
    )
    (dsf/default-action 'switch)
    (dsf/action 'exit "Exit" 'E (lambda nil (dsf/exit)))
    (dsf/cancel-action 'exit)
    (dsf/show-screen)
  )
))