The variable NEXTLINE is the index of the current entry in the table EXTRACT. It is:

• the index of the entry to be processed in the loop in the overview screen.
• the index of the entry displayed in the detail screen. It is determined via the variables FIRSTLINE and L, where:
• FIRSTLINE is the index of the first displayed line on the overview screen
• L is the line number on the overview screen on which the function F2 was called.