Z LIGHTS: Prime's answer to mobile phone torches

[StephenG1CMZ]

The cause appears to be a bug in 11586, not present in 8151 (both on Android).

In the main program, a loop on CHOOSE is examining the choose variable CHS, expecting it to be 0 if the user Escapes without selecting a choice... This seems to be the documented behaviour in the on-device help in both versions.
In 8151 as expected 0 is returned.
In 11586 the previous value is repeated.

Changing the logic so that CHOOSE returns a boolean and using that boolean to exit fixes the change in behaviour and works in both systems.