How to flip through cards in HyperCard.

cardflipper.hc

-- first approach:
-- sadly this causes a deep nested hierarchy where "go" calls "openCard"
-- which calls "go", eventually running out of memory.
on openCard
  wait 5 seconds
  go next
end openCard

-- second approach:
-- idle gets called periodically by HyperCard, but you don't have control over
-- the interval (in some HC clones you can set the idleTicks or return a tick interval)
on idle
  global gLastCardChangeTime
  if gLastCardChangeTime is empty or (gLastCardChangeTime +5) > the seconds then
    put the seconds into gLastCardChangeTime
    visual effect wipe left -- or whatever you want
    go next
  end if
end idle