What is a Subscreen ? How can we use a Subscreen ?

A subscreen is an independent screen that is displayed in an area of another ("main") screen. To use a subscreen we must call it in the flow logic ( both PBO and PAI ) of the main screen. The CALL SUBSCREEN statement tells the system to execute the PBO and PAI events for the subscreen as part of the PBO or PAI events of the main screen. The flow logic of your main program should look as follows:

PROCESS BEFORE OUPTPUT.
CALL SUBSCREEN <area> INCLUDING '<program>' '<screen>'.
PROCESS AFTER INPUT.
CALL SUBSCREEN <area>.
Area is the name of the subscreen area you defined in your main screen. This name can have up to ten characters. Program is the name of the program to which the subscreen belongs and screen is the subscreen's number.