c->button.iscancel = 0;
union control *ctrl_pushbutton(struct controlset *s,char *label,char shortcut,			       intorptr helpctx, handler_fn handler,			       intorptr context){    union control *c = ctrl_new(s, CTRL_BUTTON, helpctx, handler, context);    c->button.label = label ? dupstr(label) : NULL;    c->button.shortcut = shortcut;    c->button.isdefault = 0;    return c;}