CodeWheel: : one wheel spins within the other. A message is
typed in and the letters are subsituted to, form a sectret code,
by the letter on the inner wheel against the letter to be
subsituted position on the outer wheel. Click on the green flag
and the wheels aline A = A. Click on the inner wheel turns it
clockwise one poistion the start position. Type in the message           
and it will be coded. A silder can be set -12 to 12 so after each
letter is coded the inner wheel spins that number of positions.
(- is anticlockwise), After the message has been coded a file
appers, click on this and the coded message can be added to
the clipboard to paste into notepad etc. or can be saved as a
text file. This could be done with teams of two, the first decides
on the coding startagy and passes this to the second team.
They have to write the codewheel programme to decode
the message. What information does team one have to pass
to team two? A further possability is that the inner wheel
changes by some more complex way i.e. 1 position the first
time, 2 positions the second time etc. Or maybe 12 turn
clockwise, then 3 turns anticlockwise