A game file basically consists of a number of levels. These Two Buttons allow you to select which level from within the currently active game file is to be edited.

When you load a game file, the Title of the Window will display the file name of the game file aswell as the name of the currently active level. The index into the game file aswell as the total number of levels is also displayed.

The Actual Level Order is changed via the Game Info.. Menu Item under the Game Menu (link).

PREVIOUS The Button will move from the currently edited level towards the first level in the Game File. If you are already at the first level or there is only a single level in the game file then this button will be disabled

NEXT The Button will move from the currently edited level towards the Last level in the Game File. If you are already at the last level or there is only a single level in the game file then this button will be disabled