Can be do it in 2 way 

1, By using the TSQ

2, By using array, define a variable ( occurs clause of 5 ) 
first read the first five records from the vsam files, when 
its reaches the 5th records store the last record in the 
variable( linkage section ) and throw the map and populate 
the five records in the screen, handle the logic to start 
reading the file with the last processed record this way 
when pf7 is pressed it start reads from the last processed 
record.

If you want i can give you the sample code 

Farook