HP RPG/XL Programmer's Guide (30318-90001)

4- 36
Figure 4-21. Changing a VPLUS Form
Comments
1 This line sets the repeat/append code (RPTAPP) code to 0. Code
0 does not repeat the current form.
2 This line sets the freeze/append code (FRZAPP) code to 0. Code
0 clears the current form before displaying the next one.
3 This line enters the name of the next form (FORM2) in to the
output field, NXTFRM.
4 This line enters the VPLUS action, CHGNXT, into the action
field. CHGNXT directs VPLUS to retrieve another forms file and
place it into the VPLUS buffer.
5 This line performs exception output for the record associated
with EXCPT Group V$ACTN.
6 This line begins the description of the TERMINAL output record
associated with EXCPT Group V$ACTN.
Using Function Keys with VPLUS. This section explains how to use
function keys and function key labels with VPLUS.
You can use function keys to turn on record identification indicators
instead of using event codes to do this. (For each event code returned
by VPLUS, a corresponding function key is turned on also.) For example,
when the user enters data and presses ENTER , VPLUS returns event code
00 and turns on F0. An advantage of using function keys is that they are
automatically reset for each event. Indicators set by event codes are
not reset by READ operations and can cause erroneous results if you do
not use them properly in the program.
Figure 4-22 shows how to enable the function keys and how to use them to
identify the type of data the user enters on the terminal.