Surface *img_previous_level_bt, *img_next_level_bt, *img_previous_sector_bt, *img_next_sector_bt;
ButtonGroup *tiles_board, *tiles_layer, *level_options;
Surface *img_previous_level_bt, *img_next_level_bt, *img_previous_sector_bt, *img_next_sector_bt;
ButtonGroup *tiles_board, *tiles_layer, *level_options;