COBOL example
In my comment on the post Logical flow of an Interactive program the structure of the COBOL source code got lost, here is how it's supposed to look:
MainParagraph.
perform InitProgram
perform ProcessScreen
until EndOfProgram
perform ExitProgram
goback
.
InitProgram.
set ContinueProgram to true
.
ExitProgram.
continue
.
ProcessScreen.
perform ShowScreen
evaluate true
when EnterKey
perform CheckInput
when CF03
set EndOfProgram to true
set linkF03Used to true
when CF08
perform CheckInput
if NoErrors
perform WriteData
end-if
if NoErrors
set EndOfProgram to true
end-if
when CF12
set EndOfProgram to true
set linkF12Used to true
end-evaluate
.