# Creating Buttons

    #include <stdio.h>
    #include "graphapp.h"

    void quit(Control *c)
    {
      exit(0);
    }

    int main(int argc, char *argv[])
    {
      App *app;
      Window *w;
      Control *b;

      app = new_app(argc, argv);
      w = new_window(app, rect(0,0,200,150), "Pizza", STANDARD_WINDOW);
      b = new_button(w, rect(10,10,80,30), "Quit", quit);
      show_window(w);
      main_loop(app);
      return 0;
    }

Notes:

- Use `new_button` to create push buttons.
- The button's call-back lets you perform an action.
- The `exit` function cleanly exits the program.