c->listbox.ncols = 0; c->listbox.percentages = NULL;
union control *ctrl_droplist(struct controlset *s, char *label, char shortcut,			     int percentage, intorptr helpctx,			     handler_fn handler, intorptr context){    union control *c = ctrl_new(s, CTRL_LISTBOX, helpctx, handler, context);    c->listbox.label = label ? dupstr(label) : NULL;    c->listbox.shortcut = shortcut;    c->listbox.height = 0;	       /* means it's a drop-down list */    c->listbox.draglist = 0;    c->listbox.multisel = 0;    c->listbox.percentwidth = percentage;    return c;}