# Checkboxes

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

    void choose(Control *c)
    {
      if (is_checked(c))
        printf("Oh, you want %s do you?\n", get_control_text(c));
      else
        printf("Don't want %s now, I see.\n", get_control_text(c));
    }

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

    int main(int argc, char *argv[])
    {
      App *app;
      Window *w;
      Control *c1, *c2;
      Control *b;

      app = new_app(argc, argv);
      w  = new_window(app, rect(0,0,200,150),
                      "Pizza", STANDARD_WINDOW);
      c1 = new_check_box(w, rect(10,10,160,25), "Ham", choose);
      c2 = new_check_box(w, rect(10,40,160,25), "Mushrooms", choose);
      b  = new_button(w, rect(10,80,80,30), "Quit", quit);
      show_window(w);
      main_loop(app);
      return 0;
    }

Notes:

- Use `new_check_box` to create check boxes.
- The checkbox call-back function lets you see state changes.
- Use `is_checked` to see if a check box is currently checked.