+extern Surface* checkbox;
+extern Surface* checkbox_checked;
+extern Surface* back;
+extern Surface* arrow_left;
+extern Surface* arrow_right;
+
+extern Menu* contrib_menu;
+extern Menu* contrib_subset_menu;
+extern Menu* main_menu;
+extern Menu* game_menu;
+extern Menu* worldmap_menu;
+extern Menu* options_menu;
+extern Menu* options_controls_menu;
+extern Menu* highscore_menu;
+extern Menu* load_game_menu;
+extern Menu* save_game_menu;
+extern Menu* current_menu;
+
+/* input implementation variables */
+extern int delete_character;
+extern char mn_input_char;
+
+/* Reset the global menu variables */
+void menu_reset(void);
+
+/* "Calculate" and draw the menu */
+void menu_process_current(void);