Sub-file programming - loading a page at a time

This is the list of customers for salesperson # 1

   SALESPERSON#    1                                                            
SEL CUST      NAME                               PHONE#                         
 _  000201    ABC WIDGETS                        5551112222                     
 _  000214    AFFILIATED COMPUTERS               2145551212                     
 _  000301    APTIS SOFTWARE                     5125551212                     
 _  000115    CLINTON, WM                        2015551212                     
 _  000106    DOE, JANE                          2145551212                     
                                                                        More... 
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                       F3=EXIT