NOTE
First file in the FPG always has code 0. If your game is simple and it only has a few graphs, you can consider to keep them all in a same FPG file and load it at the beginning of your program. You can use 0 from then on in all the calls to functions that use graphs.
An FPG library maintains all its graphs in memory simultaneously. If your game is going to have a great number of graphs of great size, it is recommended that you distribute them in several FPG files that you only recover as are necessary. You can release the memory occupied by a FPG using the function
Unload_Fpg, once it is no longer necessary.