public void check() {
        if (chrlist == null)
            return;
        if (selbtn == null)
            return;

        if (chr == null) {
            chr = chrlist.opts.get(0).name;
        } else {
            String nm = null;
            for (Listbox.Option opt : chrlist.opts) {
                if (opt.disp.equals(chr)) {
                    nm = opt.name;
                    break;
                }
            }
            if (nm == null)
                throw (new RobotException(this, "requested character not found: " + chr));
            chr = nm;
        }
        chrlist.wdgmsg("chose", chr);
        selbtn.wdgmsg("activate");
    }