static void colour_handler(union control *ctrl, void *dlg,
			    void *data, int event)
{
    Config *cfg = (Config *)data;
    struct colour_data *cd =
	(struct colour_data *)ctrl->generic.context.p;
    int update = FALSE, clear, r, g, b;

    if (event == EVENT_REFRESH) {
	if (ctrl == cd->listbox) {
	    int i;
	    dlg_update_start(ctrl, dlg);
	    dlg_listbox_clear(ctrl, dlg);
	    for (i = 0; i < lenof(colours); i++)
		dlg_listbox_add(ctrl, dlg, colours[i]);
	    dlg_update_done(ctrl, dlg);
	    clear = TRUE;
	    update = TRUE;

	}
    } else if (event == EVENT_SELCHANGE) {
	if (ctrl == cd->listbox) {
	    /* The user has selected a colour. Update the RGB text. */
	    int i = dlg_listbox_index(ctrl, dlg);
	    if (i < 0) {

		clear = TRUE;
	    } else {
		clear = FALSE;
		r = cfg->colours[i][0];
		g = cfg->colours[i][1];
		b = cfg->colours[i][2];
	    }
	    update = TRUE;
	}
    } else if (event == EVENT_VALCHANGE) {
	if (ctrl == cd->redit || ctrl == cd->gedit || ctrl == cd->bedit) {
	    /* The user has changed the colour using the edit boxes. */
	    char buf[80];
	    int i, cval;

	     * return nonzero on success, or zero if the colour
	     * selector did nothing (user hit Cancel, for example).
	     */
	    if (dlg_coloursel_results(ctrl, dlg, &r, &g, &b)) {
		cfg->colours[i][0] = r;
		cfg->colours[i][1] = g;
		cfg->colours[i][2] = b;
		clear = FALSE;
		update = TRUE;
	    }
	}
    }

    if (update) {
	if (clear) {
	    dlg_editbox_set(cd->redit, dlg, "");
	    dlg_editbox_set(cd->gedit, dlg, "");
	    dlg_editbox_set(cd->bedit, dlg, "");
	} else {
	    char buf[40];
	    sprintf(buf, "%d", r); dlg_editbox_set(cd->redit, dlg, buf);
	    sprintf(buf, "%d", g); dlg_editbox_set(cd->gedit, dlg, buf);
	    sprintf(buf, "%d", b); dlg_editbox_set(cd->bedit, dlg, buf);
	}
    }
}

struct ttymodes_data {
    union control *modelist, *valradio, *valbox;
    union control *addbutton, *rembutton, *listbox;
};