AT SELECTION-SCREEN [ OUTPUT
| {ON {par|selcrit}}
| {ON END OF selcrit}
| {ON BLOCK block}
| {ON RADIOBUTTON GROUP radi}
| {ON {HELP-REQUEST|VALUE-REQUEST}
FOR {par|selcrit-low|selcrit-high}}
| {ON EXIT-COMMAND} ].
Introduces event blocks whose events are triggered at certain times during
selection processing. Without an addition, the event is triggered when selection processing is completed.