Dropdown box

The DDS for a window with a scroll bar to act as a Dropdown Box of valid values for a field
     A*%%TS  SD  19980421  153743  BOOTH       REL-V3R7M0  5716-PW1             
     A*%%EC                                                                     
     A                                      DSPSIZ(24 80 *DS3)                  
     A*                                                                         
     A          R SFLA                      SFL                                 
     A*%%TS  SD  19980421  153743  BOOTH       REL-V3R7M0  5716-PW1             
     A            APTERM    R        O  1  1REFFLD(RAPTERMS/APTERM *LIBL/APTERM-
     A                                      S)                                  
     A          R FMT01                     SFLCTL(SFLA)                        
     A                                      SFLSIZ(6)                           
     A                                      SFLPAG(5)                           
     A                                      WINDOW(16 25 5 18 *NOMSGLIN)        
     A                                      ROLLUP                              
     A                                      ROLLDOWN                            
     A                                      OVERLAY                             
     A                                      SFLCSRRRN(&RRNA)                    
     A                                      SFLDSP                              
     A                                      SFLDSPCTL                           
     A  91                                  SFLEND(*SCRBAR)                     
     A                                      MOUBTN(*ULD ENTER)                   
     A            RRNA           5S 0H                                           
     A          R DUMMY                                                          
     A                                      TEXT('PREVENTS PREVIOUS SCREEN FROM- 
     A                                       BEING CLEARED')                     
     A                                      ASSUME                               
     A                                  5  9' '                                  







The RPG to simulate a dropdown box of valid values

      *************************************************************          
      * A program to show a pick window for prompting:            *          
      *    4/98  Booth M.                                         *          
      * (Uses mouse button click)                                 *           
      *                                                           *          
      *************************************************************          
     FAPTERMFM  CF   E             WORKSTN                                   
     F                                     SFILE(SFLA:RRNA)                  
     FAPTERMS   IF   E             DISK                                      
     C*  ..................................................                  
     C     *ENTRY        PLIST                                               
     C                   PARM                    APTERM           15         
     C**                                                                     
     C                   Z-ADD     1             RRN               4 0       
     C                   Z-ADD     1             RRNA                        
     C                   READ      RAPTERMS                               58 
      * If file is empty:                                                    
     C     *IN58         IFEQ      *ON                                       
     C                   MOVE      *ON           *INLR                       
     C                   RETURN                                               
     C                   END                                                  
     C* Fill the subfile:                                                     
     C     *IN58         DOWEQ     *OFF                                       
     C                   Z-ADD     RRN           RRNA                         
     C                   WRITE     SFLA                                       
     C                   ADD       1             RRN                          
     C                   READ      RAPTERMS                               58  
     C                   END                                                  
     C     RRNA          IFGT      5                                          
     C                   MOVE      *ON           *IN91                        
     C                   END                                                  
     C                   EXFMT     FMT01                                      
     C**                                                                      
     C* If a choice was made, save it to PARM for return:                     
     C     RRNA          IFGT      *ZEROS                                     
     C     RRNA          CHAIN     SFLA                               54      
     C                   END                                                  
     C                   MOVE      *ON           *INLR                        
     C*-------------------------------------------------------------------